Hi @Arioule ,
Do you want to assign security role to an azure ad group in one environment?
You could set this in https://admin.powerplatform.microsoft.com
1)for Microsoft 365 Groups
Firstly, in azure admin center create a Microsoft 365 Group:https://portal.azure.com
Then in power platform admin center, choose the environment that you want to set, choose teams.

Choose +new to create team.
Team type choose AAD office group, copy the microsoft365 group object id in the azure ad object id part.


2) for Security Groups
Firstly, in azure admin center create a Security Group:https://portal.azure.com
Then in power platform admin center, when you create team, choose security group.

3)for Groups of users
You just need to choose owner in team type when creating team in power platform admin center.

You do not need to enter group object id in this situation. After you create team, you need to add user manually.
To assign security group, choose the team that you create, choose security role in related part.

You could assign the existing security role here.
Best regards,