how do get amazon to show a single price and not a price range with select size option?(size & color variation)

1. How to get amazon to show a single price and not a price range with “select size” option for variations?I have a listing with color and size variation, color get selected by default but it asks the user to select size instead and displays a price range.
2. How do I get them to show individual title for each child instead of the parent’s title?

I’ve tried most options including flat files