Daisy chaining survey -> Experiment -> Experiment with ID pass created by "expression" variable

I believe I may not be defining the participant ID in the survey in a way that can be passed in the URL envelope? I do not want to collect identifiers, so I am experimenting with assigning an ID in the survey using “Expression” set to not visible. For now, I named it participant and put 988 in the expression box just to pilot.

The survey end uses the chain
$“ReversalLearning [PsychoPy]”+expInfo[‘participant’]

This chaining works with the experiment URL alone, but fails when attempting to pass the participant value. This leads me to believe it may not be accurately created as I thought by the “expression” variable?

I found this discourse useful, as it contained several examples

I discovered I had added a variable “$” that was unnecessary. When I used a constant, it passed the value. The expression (e.g., rand()) still is not passing the value. The constant also will not update now (cleared cache, incognito run). There were notes that, previously, expressions could not be passed as values in the URL, but it also sounds like they now can?

I would like to avoid using the external app solution, because those dependencies are too risky if they should have unexpected down time, etc.