To be added to the administrator group of your company you would need to either:
A) Please contact a user currently in the administrator group and have them add you to the administrator group. To do this, have the administrator login to the company dashboard via:
https://dashboard.live.altium.com/
From here, select <Groups> tab at the top to enter the Groups page.
From here, select the Group Administrators. And then select the Add Users to Group option to add the email address.
Or
B) Please send a request ticket to your Sales Account Manager to have you added as a user of the administrator group.