In 18.04, have a networked Brother MFC-J870DW, which works fine in gscan2pdf, Simple Scan & Gimp 2.8. However, Gimp 2.10 can't find it. Meaning, there is no scanner listed when I select File > Create. I suspect I need to point Gimp to xsane. Looking for help to do this. Thanks.
You don't need a ppa, just
sudo apt install xsane
As you have installed GIMP as FlatPak I suggest to remove this FlatPak version with
and then install normal deb-based version 2.8 with
or get 2.10 from PPA: