How to manipulate the arrow of the dropdown (or input)?

[VictorAndrade11]

I am trying to modify the input arrow, as you can see in the attachment: https://i.imgur.com/TnmH7n3.png

However, it is not programmable (LUL).
I tried creating functions to manipulate it;
I tried manipulating it with CSS;
But I always get two results: Either it doesn't work or it breaks the code.

I need to make it possible to choose whether the arrow appears or not.

Tks

[yairEO]

hi, such questions I advise to ask on Stackoverflow, and you should also add code...