Wireguard can't route through HA?

Wireguard can’t tunnel into my HA and then out to the internet. Tailscale asks for what ‘exit node’ to use, and then your client (my phone) thinks it’s where my HA tailscale computer is. Useful for travel! But Wireguard only allows me to route to local devices on my HA computer. There is not option to route my phone, through HA, then out into the internet. “what’s my ip address” always shows traffic from my phone’s local location. Is there a secret option, or startup command, that does this?