Samsug A50 Pattern Unlock not working Android 10

my sister was using her phone normally and till yesterday, the pattern unlock stopped working. The problem is not that she forgot her pattern but rather the phone is not allowing the correct pattern to access the phone.
What I have tried:

1. Find my phone; was not enabled

2. USB Debugging is off, but I can access adb sideload and can flash files and zip both using sd card and adb

3. Tried to flash pattern-remover.zip but an error occurred saying that

   E:footer is wrong

   E:Signature verification failed

   E:error: 21
   I don’t want to factory reset it because pretty much all of her data are not backed up. If there is any options to backup and restore the data would be great, or to bypass the pattern lock. Any methods is much appreciated thanks