Start with Arnova8G2 7.3 + a dedicated Y9 Prime config.
The good news is that GCAM can be installed on the Huawei Y9 Prime 2019, but it requires a bit of technical know-how and some caution. The device's Kirin 710 processor and Android 9.0 (Pie) operating system make it compatible with GCAM, but you'll need to use a modified version of the app that's specifically designed for Huawei devices. gcam huawei y9 prime 2019
Search for: "GCam config Huawei Y9 Prime 2019 XML" — look for files named like Y9_Prime_2019_v4.xml . Start with Arnova8G2 7