They probably want to see if you finished your basement or added a bathroom. Tell ‘em “no”, if you can.
OTOH, if they have overvalued your home - then let them in to see that there is no finished basement or added basement.
If a homeowner is protesting his tax value, then any “failure to cooperate” is a deal breaker. The appraisal office will reject the tprotest and likely RAISE the value.
I had a new hot water heater installed a few years ago. The plumber came, installed, and left. He pulled a permit; standard operating procedure.
The building dept. hounded me for almost a year. They wanted to “inspect” the installation.
BS
They wanted to see if I had improved my basement.
I hadn’t.
It’s still a mess.