My Outlook for Mac don't switch to new look

Hello everybody

I have a Mac (14.5 (23F79) / Sonoma 14.5) and Outlook (16.89.3 (24092813)) installed with an active license (Office 365).

On this Outlook I have an Exchange account connected.

But my Outlook have the old look and I don't have any switch on menu to go to new look.

How can I do to switch on new look ?

Thanks for all,
Hugo Martinez