Hi Afrid!
The answer depends on where you currently at with your userbase. Do you have any customers yet? Here are a few ideas that came to my mind:
0. Build your brand (not your product brand, but your as a person) - imo having your own followers helps tremendously! Articles, interviews, anything helps!
1. I`d start by finding a few people interested in the idea already and talking to them directly. What problem you are solving for them in their opinion, where in this solution they find most value and what they are willing to pay for (and how much).
2. Market analysis can be a good hint - what is already there, what is missing in their product that yours have and how it is monetized.
3. If any expo or social events, - join if you can and pitch your idea.
4. Check open door days / any social events at local companies that might benefit from your idea. Also pitch!
Hope this can help. THe best of luck to you :)