Area "Email signature" missing in Outlook on the web

Hello, 

The "add signature" on the area Settings > Mail >Compose and Reply is missing in my Outlook on the web.

I already try to check/uncheck   "Email signature" on the OWA policies (Exchange admin center).

I dont't know if anyone has had this issue before or has any idea how to fix it.  

This is what i need : 

Thank you.