Have a look at the market place, for example this module allows you to login with your Google acount: https://marketplace.mendix.com/link/component/1414/CLEVR/Open-Authentication-Module
Hi Reece,
This might be what you are looking for:
https://www.mendix.com/blog/add-google-sso-to-your-mendix-app-using-the-oidc-module/