I don’t have any working experience with object detection algorithms and just know their concepts. But I have a source that you could refer to.

  
      
      GitHub
  
  
    

sgrvinod/a-PyTorch-Tutorial-to-Object-Detection 5

SSD: Single Shot MultiBox Detector | a PyTorch Tutorial to Object Detection - sgrvinod/a-PyTorch-Tutorial-to-Object-Detection