Re-configure gnome-keyring to be started by systemd

As far as I understand, Manjaro’s default configuration with Gnome is to run gnome-keyring via PAM. At least I’ve found the pam module being mentioned in /etc/pam.d/gdm-autologin.

I am running protonmail bridge as a systemd service and to unlock the account, it needs access to the keyring. I’d like to set a dependency in that service file on the keyring being unlocked but I can’t do that because gnome-keyring is not managed via systemd.

I don’t have much experience with PAM, so I’d rather not mess with things too much to avoid locking myself out of the system. Is there a way of how I can configure things such that applications that depend on the keyring being unlocked only start after that has happened?