Comment by n_ary
The threads here appear to parrot the old decade “find the people before solving the problems” which sadly is way out of date.
Secondly, people are now so used to online ads that the ads became a background noise to them and most ads are somehow considered “scam”.
Since you built something, it means that it solves a real problem. Now you need to build a community around it or find the community who solve similar problems.
Now about the audience, is your product for technical people(think HN/Lobsters), then do a SHOW HN/Lobsters and offer limited free seats if it does not cost too much. Meanwhile lookout on Twitter(X), Mastodon and other tech channels to promote it covertly.
If your audience is lay person, ads on radio, poster ads, small time influencer(social media) promotion will bring some interest.
If your audience is more specialized, channels like Linkedin has a group of people who will be receptive to your promotions.
Here, my examples are just handpicked.
Aside, indie hacker group is… not a good place if you do not have a large community of followers and I’ve seen most of their products(other than games) are mostly junk that their followers will buy not as a value but as a support for the person they follow and will often refer others due to implicit referral bonuses. Of course there are genuine good products from indie hackers but most of their stuff are life style stuff that do not work unless you have a massive following base and can churn out new stuff every 6 month - 2 year because due to the nature of the products they build, there are no recurring business.