How can i make images as background to other objects

hi , i am trying to put backgrounds in my dataset, as yolov5 doc advices but i dont know how i want to make my objects appear randomly on these background i tried to do that in augmentation i didnt know how, i also uploaded some images and i marked them as NULL
the matter is the objects i pick should have different background to train the model better
thank you

Here’s how to create a synthetic dataset: How to Create a Synthetic Dataset for Computer Vision