Need help with if statement

Hi there.

I'm also having problems with the if statement. I have the following formula in a formula field: if field("dod")>field("date_of_birth") then 'A' else 'B'

And can't help the below error:
Syntax error in formula 'if field("dod")>field("date_of_birth") then 'A' else 'B''

Could you please try to help me? I've tried the following, just o check, but did not work as well:

if 3>1 then 'A' else 'B'

Cheers,
Patricia