How to align matras and anchor point for indic scripts in glyphs 3

Hello, I am making a new font I don’t understand how anchor points work. I am making matras in Oriya script which should be automatically aligned to consonant glyphs but it doesn’t. Do I have to generate all glyphs and add manually from feature ? I need explanation I read a blog but it is outdated. Anyone help me please.

Can you explain a bit more what you are trying to do? e.g. I have those glyphs and this one should move there?