Installing cabin filter 2013

[interested]

I purchased a retrofit kit designed for a 2013 Silverado 2500 HD. Unfortunately the cabin air system in my particular truck is not what is shown by anything on You tube or any other on line link I can find.
The space shown for either replacing a filter or installing a new one like those of 2014 are quite different.
One video I removed appeared to be a 2014 and was a simple matter of removing the glove box to access the filter.
Another video showed removing the cover below the dash to access the filter area.
This particular truck has neither. Any suggestions regarding alternative locations or access to install one?