vivo y20 pattern lock done by great UMT TOOL

Operation : Wipe Userdata (Heuristic)
Checking for existing devices...Not Found
Turn Off phone, hold Vol UP + Vol DOWN and insert USB cable.
Some phones may need Special Boot Cable or TestPoint for EDL mode.
Found Port : Qualcomm HS-USB QDLoader 9008 (COM5)
Driver Info : Qualcomm Incorporated, qcusbser.sys, 2.1.2.7
Connecting to phone...OK
Waiting for response...Ignored
Init Handshake Sequence...OK
Hardware ID : E1601300 [E1601300] 03007300
OPK_DATA : F754F13EE91BF54295CA1FBD64D182067440B35FC41B798A53 9670EA259771BA
Initializing Protocol...OK
Sending Loader [prog_firehose_ddr.elf]...Done
Executing Loader...OK
Initiazling Storage...OK
Read : Not Allowed
Write : Not Allowed
Wiping userdata...Done
Operation Finished.


download loader from umt support section