1) Figure out your ICP
2) Figure out where they spend their time - eg dedicated forums, YouTube, particular TikTok influencer, etc
3) Make yourself present wherever they are - varies by channel, eg answering a related question on a forum and plugging your tool
If you don't know how to answer (2) or (3), pay for someone who's already embedded in that field to show you the ways. Can be influencer/thought leader, can be founder of another tool in that field, etc.