Adding Wireguard VPN to second line on iPhone?

I have dual sims in my iPhone 12, but can’t figure out how to get both to run through wireguard. Any ideas? Thanks!

Data access is only thru one network at a time and it is something the iPhone ask you to configure initially. You can still change it. The VPN will pass thru the current (only) data access available.

I don’t know about iPhones but most devices can only use one data sim at a time and you can select in settings. I’m pretty sure the same would be true for an e-Sim.