Append code to Sign-up handler (insert into) not working

Append code to Sign-up handler (insert into) not working

I added/appended this (default) code to the Helper on signup handler, but it doesn't seem to work when I test on a newly created Stage account. Is is extremely simple code.

Any ideas on why this is not working?

LIST_avdelning is a Form
TXT_avdelning is a text field

void signup(string customerEmail, map customerInfo)
{
insert into LIST_avdelning
[
TXT_Avdelningsnamn="Ekonomi avd"
Added_User=zoho.loginuser
]
}