When installing Chargent we recommend installing it for all users rather than Admin Only. The reason is that it's much easier to restrict permissions later on, and regardless of their profile permissions, users need a Chargent User license assigned to them in order to be able to see any data or use Chargent.
If you did happen to install it for admins only then you will need to update the permissions for those who need to use Chargent in your organization.
Beginning in Chargent 5.40, we have some Permission Sets that can be applied to any Profile for easier granting of access.
Don't forget to assign each user a Chargent user license as well, under Setup > Installed Packages