Brother printer/scanner on Ubuntu

On Ubuntu 20.10, my Brother MFC-9330CDW was found out of the box on the network as printer, but to use it as a scanner, I had to download the drivers from the Brother web site, and install them:

sudo dpkg -i brscan4-0.4.10-1.amd64.deb

Then use the brsaneconfig4 tool to configure the scanner:

/opt/brother/scanner/brscan4/brsaneconfig4  -a  name=MFC-9330CDW-Scanner  model=MFC-9330CDW  ip=192.168.x.y

Then the tool simple-scan was able to see it, but not to use it, it constantly reporting the following error message:

unable to connect to scanner

Adding the relevant users to the lp group helped:

sudo adduser $USER lp