Ohhhh dont get me started on pet store peoples

You got some good advice already, i suggest a few things a bit different
humidity - there is no way you could keep it where it needs to be in that kind of tank. So yes, you could do the glass, or you could cover the whole mesh with foil, then cut out the hole a bit bigger then your lamp to out it in.
Uth does nothing for pacman frogs tanksunless they are big enough to cover the whole wall, uvb is not needed too, at least yours is not albino ..... and these things are expensive, if you can return it. In practice do use uvb for pacman frogs that are not albino only as part of mtb treatment protocol
best as Dan said ceramic heaters.
so return what you can and get:
- a fogger ( zoomed one is pretty decent if you use distiled water for it)
- dome lamp and ceramic heater (60w should be suffient for your tank)
- zoomed hydrotherm ( humidity and temp controller) plug the dome lamp and fogger into it
- forget about any problems you had with temp and humidity, that thing will keep your climate spot on with night drop in temps.
all of the above you can get off amazon

substrate is ok, you dont need to stir anything, just change once in a month

water - bottled spring or conditioned tap water ( any fish tank conditioners will do, i like prime)

cover 3 sides on your enclosure to keep frog stress levels down, i think you had covered one side, dont really see in the pic and i suggest to get another hanging plant ( prefferably silk) that would hand and fall down on a ground - they love hides like that.

.... i am probably missing something..... please ask away, im here not that often, but other members hopefully respond, ill try to swing by too.
ill check what is happening to the link you mentioned

edit - and yes both your hydrometer and thermometer you can toss.... both are garbage