Using a "sum" function to calculated total contacts associated with Account

Hey!

I’m looking for some help on creating on creating a second column on my Accounts/Companies board that would count the associated contacts.

I would like this function to use an automation to read the number of associated contacts (>20) and then create an item on a different board.

Is it possible to turn a connected board column into a summary number automatically?

Thanks for any help and guidance!