In addition to the website host login and content login, digital marketers need to be added to a few of your Google services.

It is really easy to do. Alternatively you can provide the Google account login info and they can add themselves to your Google accounts as managers but remember that even though your gmail account is not needed, it is same login as for the Google Gmail that you may use.

The first step is to log into your Google account (gmail if you use it) and then go to each of the Google services below and add the digital marketers google email in the user section

Directions, if needed, for adding a user to each Google service is listed below.
How to add users in Google My Business
How to add users in Google Search Console
How to add users in Google Analytics