u/CC_______

I recently purchased an Essgoo head unit bundled with a DVR dashcam and an AHD reverse camera. Everything works well except the reverse camera. When I put the car on reverse, the head unit displays kind of like a "no signal" icon as shown on the image. I'm pretty sure with my wirings.

I've read online about changing the camera type. Unfortunately, holding the screen for 3 seconds while on reverse camera mode does nothing. I have also tried looking into Car settings > Factory, but i can't find anything related to changing the camera type. Can someone please help? Thanks