That app needs to read its credentials (for MailGun/SMTP) and configuration from ~/.config/surc-conf.yaml. Our current config location is ~/surc-conf.yaml and we are making use of home interface but @Lin-Buo-Ren thinks (and I agree) that we could make use of the personal-files interface.
So please grant auto-connection of personal-files interface to surc.
sorry for not being clear previously. The credentials are user specific and are not generated by the software, it only reads those i.e. if I install that snap on my computer, I would like to use it with my own MailGun (or SMTP) credentials and want it to send notification emails to addresses that I specify.
I guess that could work, previously I was aiming to make it work with both snap and non-snap environments but I guess this could just read from $SNAP_USER_DATA and if a person is running the code from source, then just fallback to read from the sample config.