Rover autonomus

Hello everyone, I’m new to the forum and I have little experience in electronics and programming. I’m building a land rover and would like your help. First difficulty, I’m using an H-bridge with a servo circuit to control the direction with a linear actuator. all connections were made but not working in pixhawk, I tried to test it through mission planner but without success. I don’t have an RC and the servo is connected directly to the pixhawk. can someone help me with this project?