Welcome to the Forum.
A fairly new plugin - but I believe I am getting the hang of it.
THe first step is to remove the area you need filled.
Then work with small areas to fill with the content you are looking for.
Just 15 minutes and I managed to provide this quick example.
More time spent will produce a better result. I should mention a directional blur was added to blend the colors better after the content aware fill.
I am sure this will get you pointed in the right direction. Any questions just ask.
@Ego Eram Reputo is much faster than I 😂