Google My Business
Here are 5 simple steps you can follow to add a manager to your Google My Business account. In order to continue with these steps, you must have access to the Gmail account that owns your location(s). If you do not have "Owner" access you will have to request that these steps be completed by the appropriate person, or ask them to provide you with more access to your account.
#1 Go to business.google.com
Go to business.google.com and log in to your account and select the location you would like to grant a user access to.
#2 Click on the name of your business
You will be re-directed to the front-end view of your business on Google.
#3 Click on the three dots at the top right
#4 Click on Business profile settings -> Managers
Click on Business profile settings and then Managers.
#5 Add managers to your Google My Business account
Enter user detailse and select the role, you would like to assign to that user.