Set IKEv2 VPN password using a config file

I want to change this source code in order to use information saved in a text file to connect to an IKEv2 VPN. However, i don't know if this library allows to set the IKEv2 password without using a  KeyChain reference. I want to read the password directly from the config file as string and set it to the ACNEService object.

Can you give me any insights about it?