Can I use two eSIMs on my iPhone at the same time?

All iPhone models that support eSIM can have multiple eSIMs and use Dual SIM with two active SIMs at the same time. 

At any given time you can use 1SIM + 1 eSIM or 2 eSIMs. You can store up to 8 eSIMs --> Using Dual SIM with an eSIM - Apple Support (IN)

I read your post but it’s not entirely accurate. Specifically:

An iPhone 13 or newer supports 2x simultaneously active eSIMs.

An iPhone 12 or earlier (going back to the Xs / Xr) only supports 1x active eSIM.

Ref: Using Dual SIM with an eSIM - Apple Support

No … an iPhone 13 can function as a Dual Active SIM device with only eSIMs.

I does NOT need a nanoSIM to be active in dual-SIM mode. (As “Xs/Xr” thru “12” indeed did require)

Also FYI the REST of the WORLD (outside the U.S.) still has nanoSIM trays.

We all appreciate and encourage your efforts to apprise other members, but we need to provide accurate info when doing so. It’s not “playing semantics”

The authoritative treatment on this topic — in-existence since the iPhone 13’s release over 3-years ago — remains Apple’s:

Using Dual SIM with an eSIM - Apple Support