Can't Configure Apt-Fast to use APT on Linux Mint 20

I'm using the PPA of apt-fast-stable to ensure I have the right version. At first, the installer let me choose to use APT or APT-GET during installation. I want to choose APT now to get more stable updates and insure all dependencies are getting installed. The installer now doesn't give me that choice, but defaults to APT-GET. I've tried to change this by editing apt-fast.conf in /ETC, but although I change it to APT, all that gives me is a list of options to use with APT/APT-GET.
I've also removed and reinstalled several times, all to no avail.
Appreciate help.