"the serial is not match fastboot_unlock_verify fail" typically occurs on Oppo and Realme devices when you attempt to enter Fastboot mode

Leo stared at the black screen of his OPPO phone. The funky neon boot logo was gone. In its place, cold, white text on a black background.

To help find the exact tool or firmware version you need, let me know: What is your specific ? Which Android version is currently running on the phone? Is it a Qualcomm or MediaTek processor?