As far as I can tell I have been through this process - I also tried all the things in the string from earlier, using a Stripe product that I had created from Discourse and that didn’t produce a subscription in Discourse.
Given it doesn’t say you have to use a discourse link to ask people to subscribe and there is a Stripe product I’m surprised this is a requirement. I tried using the link directly https://endurancebikeandrun.discourse.group/s/prod_Q7HmrlJPQP21K6 but when I try to subscribe from there I get an error message, invalid coupon code, please try again.
Are you saying that people have to be able to login to discourse so that they can subscribe? I am on another site that uses Discourse and I am sure that isn’t how I joined the group. I subscribed and then got access.
I am a paying user of Discourse so a bit unhappy that the instructions don’t appear to match my experience, although I am not a professional developer.