Slackbot does not function and I see that No web socket url returned by Slack about jbot HOT 3 OPEN

# jbot
spring.profiles.active=slack
spring.jackson.property-naming-strategy=SNAKE_CASE
logging.level.me.ramswaroop=DEBUG
server.port=8080

# slack integrations
slackApi=https://slack.com/api
slackBotToken=<paste your slack bot token>             # <-------------- your token here

2021-02-07 17:34:55.510  INFO 4181 --- [           main] example.jbot.JBotApplication             : Starting JBotApplication on Philipps-MBP with PID 4181 (/Users/pseeger/git/jbot/jbot-example/target/classes started by pseeger in /Users/pseeger/git/jbot)
2021-02-07 17:34:55.513  INFO 4181 --- [           main] example.jbot.JBotApplication             : The following profiles are active: slack
2021-02-07 17:34:55.551  INFO 4181 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@3feb2dda: startup date [Sun Feb 07 17:34:55 CET 2021]; root of context hierarchy
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils$1 (file:/Users/pseeger/.m2/repository/org/springframework/spring-core/4.3.2.RELEASE/spring-core-4.3.2.RELEASE.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2021-02-07 17:34:56.245  INFO 4181 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2021-02-07 17:34:56.253  INFO 4181 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2021-02-07 17:34:56.254  INFO 4181 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.4
2021-02-07 17:34:56.300  INFO 4181 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2021-02-07 17:34:56.300  INFO 4181 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 753 ms
2021-02-07 17:34:56.455  INFO 4181 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2021-02-07 17:34:56.461  INFO 4181 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2021-02-07 17:34:56.462  INFO 4181 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2021-02-07 17:34:56.462  INFO 4181 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2021-02-07 17:34:56.462  INFO 4181 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2021-02-07 17:34:56.508  INFO 4181 --- [           main] m.r.j.c.c.c.DefaultConfiguration         : There are no any rest template beans defined, creating default rest template...
2021-02-07 17:34:57.298 ERROR 4181 --- [           main] me.ramswaroop.jbot.core.slack.Bot        : No web socket url returned by Slack.
2021-02-07 17:34:57.585  INFO 4181 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@3feb2dda: startup date [Sun Feb 07 17:34:55 CET 2021]; root of context hierarchy
2021-02-07 17:34:57.610  INFO 4181 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/slash-command],methods=[POST],consumes=[application/x-www-form-urlencoded]}" onto public me.ramswaroop.jbot.core.slack.models.RichMessage example.jbot.slack.SlackSlashCommand.onReceiveSlashCommand(java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String,java.lang.String)
2021-02-07 17:34:57.611  INFO 4181 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2021-02-07 17:34:57.612  INFO 4181 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2021-02-07 17:34:57.628  INFO 4181 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-02-07 17:34:57.628  INFO 4181 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-02-07 17:34:57.650  INFO 4181 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2021-02-07 17:34:57.783  INFO 4181 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2021-02-07 17:34:57.811  INFO 4181 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2021-02-07 17:34:57.814  INFO 4181 --- [           main] example.jbot.JBotApplication             : Started JBotApplication in 2.585 seconds (JVM running for 3.119)