well, is very rare to find someone that needs music for their games in itch.io (you usually find people who wants to put their music in games actually), so if you want to get paid with music, your best option is to level up and start making music for more stuff other than games only... consider freelancing. There are sites like fiverr where you can be paid to make something for someone, and sites like soundbetter, which are more intended for music. Also, consider stock music sites like audiojungle, people pay to be able to use a song in everything they need (more passive money, what usually means a chiller income source in exchange of less money)