To check if your device supports eSIM:

For iPhone: 

Go to [Settings] 

Select [General] and then choose [About]. 

Scroll down and look for the eSIM section. 
 

If your phone supports eSIM, you will see IMEI information related to eSIM. If not, your phone does not support eSIM.

Or you can check as follow

Go to [Settings] 

Select [Cellular]. 

Then scroll down a little bit to find the SIMs section. Here, if you see the [Add eSIM] or [Add Cellular Plan], then your device is likely eSIM Compatible. 

For Android:

First, locate to [Settings]

Find and select the [IMEI] Information section (or similar). 

If you can't find the IMEI Information section, you can use the search function within [Settings] and type 'IMEI' to locate it quickly. 

If you see information about eSIM, it means that your phone supports eSIM.

eSIM ONE – One touch to the world

How to install eSIM: https://esimone.com/check-device

Check Compatibility: https://esimone.com/check-device