First thing make sure your iPhone supports eSIM and is an unlocked device. Then follow the the steps below:
Go to Settings > Click on Mobile Services
2. Click on Add eSIM
3. Click on QR code
4. Print or Save a QR on another device and Scan it
Or, Click Enter Details Manually to manually add details
5. Enter the SMDP+ Address or Activation Code and click Next
6. Your eSIM is ready, setup in the next article.