Stable Diffusion

I use SD to make character portraits for TTRPGs online and I’ve had decent luck fixing images with Photoshop (Beta) generative fill. It’s good at some things, like replacing one eye so that it better matches the other. It’s okay at noses. It’s very bad at mouths. It’s good at removing backgrounds or replacing something with background. Extending images is 50-50 but it can be nice for getting a character centred in frame, or for filling in the top of their head if it was cut off. It’s also pretty good at blending two images- for example, I often have a good full body image with a really weird face; it makes it a lot easier to paste a different face on top and blend the edges.

I know this is a paid option for what you’re asking but hopefully it helps.