AI-generated backgrounds are designed to suit the lighting and shadows in your photos. That's why it is usually better to have similar AI backgrounds for your photos rather than identical backgrounds.
For example, here we have 2 similar AI backgrounds, used on promotional photos for perfumes. They are not identical backgrounds, but they look like part of the same photoshoot.
There are several different ways to use similar AI backgrounds on a collection of designs:
Create a template that has the AI background and apply the template to new photos. For details, see Create a custom template.
Add the AI background to your brand kit and then insert it from there into other designs. For details, see Save an AI background to your brand kit and Use a brand kit AI background in a design.
Create a batch of images and then apply an AI background to them. To learn about editing images in a batch, see Edit multiple photos at once with Batch Mode. You can also create a template with an AI Background and apply that to a batch of images.
These are the main three ways of creating many images with similar AI backgrounds. Give them a try and see which approach works best for you.