In aiohttp, pass proxy="http://username:password@IP:20001" on the get or post call. Authentication can also go separately, in a proxy_auth with the username and password.
Many at once
Limit concurrency with a semaphore. Firing a hundred requests together through the same address is the fastest way to get blocked by the destination, and the address is not the bottleneck.
SOCKS5 needs its own connector and uses port 20481. The proxy parameter only covers HTTP.