Try contacting the original device manufacturer. Many obscure ICs are custom-marked – the EC5377U-872 could be a rebranded STM32, NXP, or Microchip part. Decapsulation may reveal the true die.
Once in the bootloader, try:
There is no universal “one-click” tool for the EC5377U-872 unlock. Depending on the hardware and lock mechanism, you may need to use one or more of the following approaches. ec5377u-872 unlock