email/tweet/etc indie rappers you like
often you can pay for verses, but if they dig your stuff and aren’t super well established, they’ll probably be happy to work together for free
see if you have a hip hop / rap open mic night where you live. Most amateur emcees are hungry for original beats.
Also, while I really liked what you did in this track… if there are no “drums”, it might be hard to find an emcee willing to work with it 
There are also tons of a capellas available, which are a great way to build your “resume” and/or get a feel for working with raps til you find someone IRL/online to work with!
signed, someone that’s worked with ~3 emcees in their life to various degrees of success