I got Angelfish installed on the Jolla Phone 2 with Sailfish OS 5.2.0.13 by doing the following:
Installing zypper (if not already installed)
devel-su pkcon install zypper
Adding repositories.
devel-su ssu ar 'piggz-qt6-apps' 'https://repo.sailfishos.org/obs/home:/piggz:/qt6apps/sailfish_5.1_aarch64/'
devel-su ssu ar 'piggz-qt6sb2' 'https://repo.sailfishos.org/obs/home:/piggz:/qt6sb2/sailfish_51_aarch64/'
devel-su zypper refresh
Download additional rpms from CHUM to ~/Downloads/ and install them via zypper command.
https://repo.sailfishos.org/obs/sailfishos:/chum/5.0_aarch64/aarch64/qt-runner-0.4.6-1.9.1.bso.aarch64.rpm
https://repo.sailfishos.org/obs/sailfishos:/chum/5.0_i486/noarch/qt-runner-qt6-0.4.6-1.9.1.bso.noarch.rpm
devel-su zypper in ~/Downloads/qt-runner-0.4.6-1.9.1.bso.aarch64.rpm
devel-su zypper in ~/Downloads/qt-runner-qt6-0.4.6-1.9.1.bso.noarch.rpm
Installation
devel-su zypper in angelfish
Deinstallation
#Uninstalling packages
devel-su zypper rm -u angelfish
devel-su zypper rm -u qt-runner-qt6
devel-su zypper rm -u qt-runner
#removing repositories
devel-su ssu rr 'piggz-qt6-apps'
devel-su ssu rr 'piggz-qt6sb2'