How to transform "dot" to "slash"?
to_char(MyDate, 'DD/MM/YYYY') is the correct answer
(or to_char(MyDate, 'DD;MM;YYYY') if you want ; instead of /)

Beware : MyDate must be a timestamp zone.

If MyDate is a Date Zone, you should code

to_char(timestamp_iso(MyDate), 'DD/MM/YYYY') 

(or to_char(timestamp_iso(MyDate), 'DD,MM,YYYY') if you want , instead of /)