To grant access to your Google Play account you need to:

1. Login to your Google Play developer account.

2. In the sidebar menu click "Users and permissions" link.

3. On the "Users and permissions" page, click "Invite new users" button.

4. On the "Invite user" page, enter our email address "[email protected]" and in "Account permissions" tab tick "Admin (all permissions)" checkbox. 

5. Next click "Invite user" button to send invitation.

6. All done.

Learn more about Google permissions here.

Screenshot - Users and permissions

Screenshot - Invite user