Try getting someone famous (in relevance to your target/desired audience) to post that they are on your platform (be sure to make sure that the platform works and gives value before approaching them - otherwise nothing you do will work).
p.s.: before launching, did you actually check that there was a need for this platform (no offence, but this is crucial to know before)?
I've successfully helped over 380 entrepreneurs, startups and businesses, and I would be happy to help you. After scheduling a call, please send me some background information so that I can prepare in advance - thus giving you maximum value for your money. Take a look at my reviews: https://clarity.fm/assafben-david