changle thumnail url

hello sir, I hope you are ok. I am a developer. I am trying to create a wordpress theme for my customer. My custom integrate rankmath with custom theme.

She add thumnail by custom field post feature image.

e.g. https://img.rapcab.com/movie/2023/01/1531.jpg

“https://img.rapcab.com/” set as default & custom field provide remain portion “movie/2023/01/1531.jpg” get by custom “post-img-url”

But rank math doesn’t take the feature image & display rankmath default image as feature image everywhere.

So i need to implement custom field as feature image or change thumbnail url by custom field. I hope give a function to change this as soon as possible.

The page I need help with: [log in to see the link]