I have Office 365 E5 License.

In Power Apps, i am not able to create new environment and tables in Model-driven App.
In canvas app, the license details are showing as "Standard".
But, In Model-driven app, the license detail are showing as "Premium". How it is possible...?
What is power apps office 365 plan 3
It is possible to create new environment using office 365 plan 3..? if not, what license i need to get and to whom to i have to contact...?
pls. respond this..this is urgent and i not able to do any environment setup..