A "fixed" ROM requires a compatible version of TWRP (Team Win Recovery Project) . Ensure you have the version specifically ported for the A37m.
(Optional) If your ROM doesn't include Google services, flash the GApps package immediately after the ROM. oppo a37m custom rom fixed
Move the ROM .zip file and GApps (Google Apps) to your SD card. A "fixed" ROM requires a compatible version of
Return to TWRP and perform a Factory Reset . This usually fixes issues caused by leftover data from the previous OS. Conclusion oppo a37m custom rom fixed