How do I use additional parameters for a navigation collection

We're on PeopleTools 8.59, PUM 9.2 with Campus Solutions.

I'm trying to use the Navigation Collection - Additional Parameters to pass in a parameter at runtime to a component within a navigation collection. I add the parameter as "parm1=test" (without the double quotes) into the additional parameters field in the nav collection configuration but when I try to pull the value in page activate PeopleCode on the target component I'm not finding a value in the parameter, nor do I see the parameter in the URL.

The PCode I'm using is as follows:

Local string &TextId = %Request.GetParameter("parm1");

MessageBox(0, "", 0, 0, "TextId " | &TextId);