New to Tailscale, encountering a gateway issue

Hello,

I recently started experimenting with Tailscale, and I want to send a file from a Windows 11 machine to an iOS device. However, when I try to send the file, I encounter an immediate "502 Bad Gateway" error. I'm not terribly familiar with networking or homelabbing at all. Are there any obvious settings I need to verify before trying to send data between devices?