New to Reddit and already in over my head

So, I'm trying my very best to find relevant people who would test out my new sign-up tool. I've tried to post on specific groups that match the people that would actually find it useful.

However, there is one person who comments, on every post I make - wether it be a post in the group or a comment to some of the members, that I am in violation of rule #4:

• This is not a marketing venue.

Please do not link to your shop or website that has a link to your shop in the original submission - use an image hosting site like imgur.com instead. However you may provide a link to your shop only if another user requests it.

I do not link to any site, however I mention the name of the platform. Is that enough to say, that I am i violation of that rule?

If not, how should I react?

Is there any way I can send out a post in a group, so all members can see my request or is the only way forward to DM people on at a time?

I do not wish to violate any rules - so I am writing to get knowledge on how to use Reddit properly.

Are there specific subreddits that match what I am searching for, perhaps?

I would really appreciate your advice on this matter!