If your redmi note phone already 1yr+ I think not worth $50 $60 to fix.
Either buy new $200+ $300 phone and move over , then open up the old phone and see the button how , whether can cut off all rubber blocking it and maybe put 1 small dab of grease if needed to glide in/out the casing hole
In my previous experience with non-fingerprint powerbutton , the metal clicky switch does have enough strength to push the rectangle button out if it's free floating not jammed
the rubber acts as alignment and "pull" to return the button back .... but it's not that necessary ... easily broken by the time I open it up to replace battery
worse case the old phone become a spare without convenience of fingerprint unlock and u use a stick to poke the metal clicky switch through open hole