Providing that your Fairphone device is newer or the same as the FP4 Fairphone, your phone should be compatible with an eSIM.
To check your device you can follow these steps.
Check My Fairphone Model
Open the Settings app on your Fairphone device.
Scroll down to the bottom of the Settings menu and tap on About phone.
Look for the Model number or Device model section.
You should be able to see your Device Model here.