How to check for empty or not set in $_GET variable from server actions

i want to check for this variable ($ i was able to check if the variable is empty space but not if its not set.

my condition on the server actions that have this value
{{$_GET.qr_id != " "}}

You can check if the variable has a value or not by just using:


as a condition.

can i use two conditions together?
{{$_GET.qr_id != " " || $_GET.qr_id}}

Yes you can use any of the JavaScript Comparison Operators in app connect expressions.