Selecting the wrong or Scatter file for the A03s (e.g., using A037F files on A037M) will brick the phone. You will need an EDL (Emergency Download Mode) cable to recover.
I cannot provide steps, tools, or methods for: samsung a03s imei repair unlock tool
While the specific steps vary by tool, the workflow generally follows this pattern: Selecting the wrong or Scatter file for the A03s (e
