2FA through WAN but not LAN

[besgum]

Hi all! I have a domain pointing to my server, with nginx reverse proxy, cloudfare and SSL. All is working well, what I want is to use 2FA only outside my home and not on lan. Is there a way to do this? I´m not able to install a VPN on my job computer, so I need to expose the server to the web, but I want more security
I found its easy to add 2FA using TOTP gui, but nothing regarding my inquiry

Thanks for the guidance!!