In qBittorent, click on Tools and then press Options
In Options window, click on Connection
From Proxy Server section, choose Type SOCKS5.
Get SOCKS profile and credentials (requires a pro account).
Check mark the box next to “Authentication”. Input Host Server address, Port number, Username and Password as provided on the SOCKS5 Profile Generator page.
Check mark the boxes: Use proxy for peer-to-peer connections, Disable connections unsupported by the proxy. Press Apply then OK button once you finish.