How to use tunnel/access through has two internet connection in a single machine

I am running cloudflare service in my server and able to access my domains/subdomain applications/services etc through Access/tunnel method.

I have two ethernet interface in my server and each internet is connected to its own internet (two modems, two ISP), I would like know, how to configure cloudflare to use two internet connections such that, one subdomain ( shall be accessed through internet connection A, subdomain ( through another another internet connection B.

Please let me know if further information is required.