Download the RPM from https://repo.sailfishos.org/obs/sailfishos:/chum/4.6_aarch64/aarch64/sailfishos-chum-gui-0.6.9-1.10.1.jolla.aarch64.rpm, install, open Settings inside Chum app and set Sailfish version to 4.6.0.15.
Download the RPM from https://repo.sailfishos.org/obs/sailfishos:/chum/4.6_aarch64/aarch64/sailfishos-chum-gui-0.6.9-1.10.1.jolla.aarch64.rpm, install, open Settings inside Chum app and set Sailfish version to 4.6.0.15.