Pixscan help needed

[bobble21]

Hello, hope you are all keeping well.
I'm trying, at last, to set up the pixscan mat.
I tried printing out the calibration test card and the page printed out with only 3/4 of the paper covered in dots.
I still took a picture of it but my picture wasn't of a high enough resolution.
So I tried scanning the mat with my printer but there's no scanner showing, just says 'no scanner found'
I can't find out how to get the scanner recognised.
Also I don't know how it can work using a scanner because the mat is to big to scan it all?

I feel I'm being thick but if you can help I'd be grateful. If it won't work can I just use the mat as a normal mat so it's not wasted