Custom HTML list ID input
We're building a pop-up using OptinMonster with custom HTML for the form - not the shortened default embed code.
We've been able to test everything correctly, except how to add those who complete the pop-up to a static list. Below is the code we use to identify the form, but changing "formid" to "listid" doesn't seem to work.
<input type="hidden" name="formid" class="mktoField mktoFieldDescriptor" value="AAA">
Any assistance would be greatly appreciated. Thanks!