Getting a mobile number to get a bank account while not in Portugal!

Can anyone recommend a mobile sim option like Free in France that charges a very low monthly fee in return for a small amount of phone calls. texts and data. Really it will be used for verification purposes and Millennium Bank seems to require it.

Ideally I would like an E-sim and to get it before I arrive in Portugal. Free (the French version - is only 2€ a month and I don’t have to use it to retain the number so it is perfect in France but I need the same in Portugal.