Thank you for your script, worked well on 2nd try :) I want to suggest to add the final button submission at the end. Copied from Firefox Network requests as "Fetch"
await fetch("https://store.steampowered.com/saleaction/ajaxopendoor", {
"credentials": "include",
"headers": {
"User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0",
"Accept": "application/json, text/plain, */*",
"Accept-Language": "en-US",
"Content-Type": "multipart/form-data; boundary=---------------------------37657122792281954784964272617",
"Sec-Fetch-Dest": "empty",
"Sec-Fetch-Mode": "cors",
"Sec-Fetch-Site": "same-origin"
},
"referrer": "https://store.steampowered.com/sale/clorthax_quest",
"body": "-----------------------------37657122792281954784964272617\r\nContent-Disposition: form-data; name=\"sessionid\"\r\n\r\n<24 chars hex session id>\r\n-----------------------------37657122792281954784964272617\r\nContent-Disposition: form-data; name=\"authwgtoken\"\r\n\r\n<32 hex chars>\r\n-----------------------------37657122792281954784964272617\r\nContent-Disposition: form-data; name=\"door_index\"\r\n\r\n11\r\n-----------------------------37657122792281954784964272617\r\nContent-Disposition: form-data; name=\"clan_accountid\"\r\n\r\n39049601\r\n-----------------------------37657122792281954784964272617--\r\n",
"method": "POST",
"mode": "cors"
});
{"success":1,"rewards":[{"door_index":11,"icon_url_large":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkagcB5rige1Vh1feYKW4Tutq3zNiPkvGhZuyBwz8D6ZUi37iZpt_30QX6oQM7H2kOYyM","icon_url":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkagEO7r_0KgYyh6CdcDsWtI_nloWKlPb3YeqEzm1Q7ZF00uyZo9us2AP6oQM7uvfYLq4","name":"Steam 3000","descriptions":[{"value":""}]},{"door_index":11,"icon_url_large":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkagcD4u3yelNl1fKRJm0R74i1xNDbwPasYOqHxzkG65Qjj-iR8d-njgD6ux071n_pa3U","icon_url":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkalMDsrj8KVQwgqXMcGkavorjxtfYxKesN-ODwjkBvpck2riUrdX03wH6ux07FqP-k5Y","name":"Steam 3000 (Avatar Profile Frame)","descriptions":[{"value":"Steam 3000"}]},{"door_index":11,"icon_url_large":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkagVT4-vyfAI116OacztG7d3ix4bbzqPwYOqFzm8Cv8Yj3O_DotyjjgP6oQM7VtN-cM8","icon_url":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkagVT4-vyfAI116OacztG7d3ix4bbzqPwYOqFzm8Cv8Yj3O_DotyjjgP6oQM7VtN-cM8","name":"Steam 3000 (Profile Background)","descriptions":[{"value":"Steam 3000"}]},{"door_index":11,"icon_url_large":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkalZU5byjLgU10PGbIGUU7djgxIXaxfT1Z-yEw24GvZ0jiOiS84qh31L6oQM7viPrPlc","icon_url":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkalZU5byjLgU10PGbIGUU7djgxIXaxfT1Z-yEw24GvZ0jiOiS84qh31L6oQM7viPrPlc","name":"Steam 3000 (Mini Profile Background)","descriptions":[{"value":""}]},{"door_index":11,"icon_url_large":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkagBVs-73KQJl0vGdd2sRvt_vwtCJz66tZOKDwDtSupMii7nA94_321D6oQM7cRmVEKo","icon_url":"-9a81dlWLwJ2UUGcVs_nsVtzdOEdtWwKGZZLQHTxH5rd9eDAjcFyv45SRYAFMIcKL_PArgVSL403ulRUWEndVKv_h52CCwgkagACtLn8elI01_HOKThH6tiwzdXSwK-lNe7QwGkGu5Ym37nAp9WmjgT6rBo6zBkXWe8","name":"Steam 3000 (Animated Avatar)","descriptions":[{"value":""}]}],"sale_pg_background_override":"https:\/\/cdn.akamai.steamstatic.com\/store\/promo\/summer2022\/reward\/kiof12_clorthax_redemption_10.jpg?t=5","sale_pg_background_webm":"https:\/\/cdn.akamai.steamstatic.com\/store\/promo\/summer2022\/reward\/kiof12_clorthax_redemption_10.webm?t=5","sale_pg_background_mp4":"https:\/\/cdn.akamai.steamstatic.com\/store\/promo\/summer2022\/reward\/kiof12_clorthax_redemption_10.mp4?t=5","sale_pg_context_token":"#Summer2022_reward_quest_10","story_image":null}