If there are no conditions, you can try box push-ups. Under the same weight, box push-ups are better than barbell bench presses.
The following is Baidu's information
Box push-ups are a kind of push-ups, the main purpose of which is to better stretch the pectoralis major.
Method:
1. Prepare three hard boxes or similar items (as long as they can be placed on the ground smoothly, such as stools, etc.). )
2. Put your hands on a box (there should be a certain interval between boxes, at least wider than your shoulders) and your feet on a box (mainly to keep your feet and hands on the same horizontal plane to avoid dispersing the pressure on your chest muscles).
3. Start doing push-ups (when the arms are bent, the body should be lower than the horizontal plane where the box is located to stretch the pectoralis major)
I hope I can help you.