Only the global admin is able to add users to the workspace.

[TonyStark007]

A user who is having admin rights to that workspace is not able to add other users to that workspace. 

[aj1973 · Accepted solution]

Hi @TonyStark007 

It's a feature that needs to be Enabled By Power BI Admin of the Tenant. You can ask the Tenant's Admin to allow you to add Workspaces

[v-rongtiep-msft · Accepted solution]

Hi @TonyStark007 ,

Please understand the permissions of the different roles.

If one of the workspaces is in a shared capacity, everyone you add to it needs a Power BI Pro or Premium Per User (PPU) license. These users can all collaborate on the dashboards and reports in the workspace. 

Roles in workspaces in Power BI - Power BI | Microsoft Learn

If it does not help, please provide more details.

Best Regards
Community Support Team _ Rongtie

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[aj1973 · Accepted solution]

Hi @TonyStark007 

It's a feature that needs to be Enabled By Power BI Admin of the Tenant. You can ask the Tenant's Admin to allow you to add Workspaces