Varnish support?

I’m implementing Varnish 7 in front of our site running a mix of PHP and WP. The 2FA plug-in doesn’t seems work in this scenario. I get to enter the 2FA number, hit enter, and I’m redirected back to the login page? No error. Seemingly a loop.

It works fine on current site, with no Varnish. I assume it’s configuration problem on Varnish, any suggestions would be helpful.

Thanks!