Synchronize consecutive write/read request and reporting about up HOT 1 OPEN

As we see this command as an example.
docker run --rm -p 8080:8080 quay.io/observatorium/up --endpoint-write=https://example.com/api/v1/receive --period=10s --name foo --labels 'bar="baz"'

I see something for tenant IDS which I can use.
-tenant string
Tenant ID to used to determine tenant for write requests.
-tenant-header string
Name of HTTP header used to determine tenant for write requests. (default "tenant_id")

Question:

1. How to send user ID and password as part string for connecting Thanos.
   under usage section, couldn't find the values for authentication.
   Please help to find the same.

headers:
basic_auth:
username:
password:

from up.