Since custom ROMs usually don't include Google services, you will need to flash an OpenGApps package (select ARM, Android 10, Nano or Pico). The Story: Breathing New Life into a Legend
. While these ROMs can breathe new life into older hardware, they are often considered "alpha" or "experimental" for the S3 due to hardware limitations like 1GB of RAM. Available Android 10 Custom ROMs LineageOS 17.1 (Unofficial) samsung s3 custom rom android 10 link