How to find creators to work with
Look at what a creator makes and who it's for before you ask them to try or promote your product.
A creator with a large audience isn't automatically the right person for your product. The useful question is whether their viewers would care about what you make.
If you're building a developer tool, a small creator who regularly teaches the exact problem you solve may be worth a closer look.
Search for the topic they cover
Try a request like this in ReacherX:
Find creators on X/Twitter and LinkedIn who teach solo developers how to launch web apps. I'm looking for people who share hands-on tutorials, not just general startup advice.
Then open their work. What do they explain? Who asks questions in the replies? Do they review products, teach with them, or mainly share opinions?
Those details should influence what you ask them to do. A tutorial creator and an interviewer may need very different proposals.