Decimal format in excel online

Hello,

I have an excel file stored in my onedrive that I edit either in the desktop application or in microsoft 365 online.

I have a problem with the format of the decimal numbers.

In the desktop version, if I press the ". Delete" on the numpad, then the number 25.5 is displayed (for example) and the decimal is displayed with a comma (i am in France).

When I am in the same file online, on pressing the ". Delete" the decimal is displayed with a point.

How to make the decimal format also with a comma (in French format)?

Thanks