iPhone has 2 IMEIs but only 1 sim slot: which one to use for porting?

Although this might appear as a foolish inquiry, it can be quite perplexing for individuals like us who possess two sets of numbers.

To clarify, I possess one physical SIM card and an eSIM. Unfortunately, I couldn't locate any information indicating which IMEI corresponds to the eSIM and which one belongs to the physical SIM.

Moreover, I'm unsure about the scenario where multiple eSIMs are involved—would each eSIM have a distinct IMEI?

My intention is to transfer my number for my eSIM.

Thank you.