eSIM support is built into the hardware, so a software update won’t add it. Most phones from the last few years have it:
- iPhone: XS / XR and later.
- Samsung: Galaxy S20, Note 20, Z Fold / Z Flip and later.
- Google: Pixel 3 and later (Pixel 3a included).
- Others: many recent Oppo, Xiaomi, Sony, Honor and Motorola models.
The quick check: look for Add eSIM in your phone’s mobile or SIM settings. Your phone also needs to be unlocked.