Sounds like you are on a legacy plan that was deprecated two plan iterations ago. When plans are changed, you are not automatically upgraded to the newest plan. I suggest creating a new free plan, duplicate your app, and then copy the duplicate to that new plan.
If you have a web location for images and a public url to those images, then you can include the url in your data and it won’t count against your storage quota.
If you still want to upload images through the app, and have the images stored elsewhere, then I’m not sure there is a good solution because the free plan does not include integrations or updates. Adding a flow to process the images stored in glide, store them in a different location, and update the new url in the table would be difficult on a free plan.