Going back with a Focus Brailledisplay

Hey guys,
I've got a Focus 40 Blue Braille Display and I'm not sure, how to go to the previous page in Safari or in other apps.
In iOS the left selector is programmed to perform this task but not in MacOS. I've found a solution for a different keyboard-layout by creating a script to simulate the keystroke of the needed hotkeys. This approach didn't work for me, possibly because I'm using a QWERTZ keyboard.
Do you have a suggestion, what I could do to fix this issue?
Thanks and kind regards
Sizou