How much it will charge to change a motherboard of macbook pro 14' 2021?

What it will cost will differ for the problems you have.

Contact - Official Apple Support to discuss service options and to get a price indication

Auntu00 wrote:

How much it will charge to change a motherboard of macbook pro 14' 2021?

Contact the authorized repair facility at your location and ask them. This is a global community and we are computer users not Apple authorized repair technicians.

Three years ago it costs $592US to replace the board on my 2016 MBP 13" no touch.

The price of a new 14-in MacBook Pro unless you get a more firm cost estimate from those that can provide it — Apple Store, or Apple Authorized Service Provider.