Just managed to download your model.
Here’s the model after I’d double clicked on the reversed front face several times - it IS quite deeply nested - wrong assumption on my part.
R click - Reverse faces.
If you need to, re-apply the image using the Paint Bucket tool (shortcut b for paintBucket) from the Materials panel (this is what it looks like on Mac desktop SU 2020, may be different on Free - I’m not very familiar with it). The selected texture is faintly highlighted in blue. Drag that over the facade and click to paint it.
But it may just transfer the image from the back to the front face. Either way, you end up with this: the facade image on the central face.
It’s now slightly misaligned, so click once on the face and R-click and choose Texture.
(If you don’t see that option on the R click menu, make sure you have only selected one face, and no edges or other faces and try again.)
(Sorry for sporadic updates - I keep clicking Save Edit when I haven’t finished, and don’t move my mouse far enough to click on the SU window which is what I intended to click on).
Then drag the texture to position it properly.
And click Done to finish.
I know you don’t have Outliner in SU Free, but this is what it shows - the face with the central facade is nested a couple of levels deep in the model.
Does that help?
I know the SU Free interface is different but the same names for the same tools apply, and on the left you can search for them. And the R click menus are the same as on desktop.