SMM marketing agency?

Hi, friends! My software needs to run targeted advertising on Facebook and YouTube. Unfortunately, I don't have enough experience in this, as I am not an SMM specialist. I tried to place ads on my own, but got a few bans. So I decided to turn to professionals.

Can you recommend any advertising agency that will work with a startup and a not very large advertising budget? It is desirable to specify the terms of cooperation if you have already worked with them. I wouldn't want to fall for scammers, there are quite a few in this field(