Administrators are managed from the Citrix Cloud console. If a non-Admin wants to be added as an Administrator to an existing Citrix Cloud account, they must be invited by the existing Cloud admin.

On the Identity and Access Management page, click Administrators. The console shows all the current administrators in the account.
Note: If all admins in Citrix Cloud have left the organization or unable to locate an admin internally, please contact Customer Service via Live Support.
Note:
If the administrator already has an account, Citrix Cloud prompts them to use their existing password and sign in. After accepting the invitation, the administrator receives a welcome email and Citrix Cloud shows the administrator as “Active” in the console.
When you add administrators to your Citrix Cloud account, you define the administrator permissions that are appropriate for their role in your organization. However, from time to time, you might need to assign a different level of access to an existing administrator.
To change existing administrator permissions:
Invite and Manage Citrix Cloud Administrators