Trying to configure a custom quantity selector ( + , - )

Hey,

I’m trying to get this ± selector inside the cart to work:

I know I need custom code but I’m lost at where to start or where to look at.

Background: I will export this site with udesly to turn it into a shopify theme so it needs to be connected. The quantity value itself is connected already but I’m not sure if increasing the quantity through a script will increase the actual quantity later in shopify.

I contacted the udesly support but they usually take a month to reply.

Maybe you encountered a similar issue.

Greetings from Germany,
Timo