Change APN of GSM connection

I'm trying to change the APN of my GSM connection but don't know how to do it, googling didn't really help. This is my current connection: NAME UUID TYPE DEVICE Vodafone Default 7730a562-f660-4537-974f-defb7ceecee6 gsm cdc-wdm0 It has an APN defined (obviously) but I don't know where I can modify it. I looked into the /etc/ppp/ directory already but didn't find anything useful. Also, is it possible to change this with the NetworkManager (e.g. creating a new connection with a new APN)? Because I tried creating a new connection (with nmtui) but didn't see a possibility to create a GSM connection, just wifi etc. Otherwise, do you have an idea where I should look? Thanks for your help in advance! Fabian