You can go to manage booking > pricing tab  > change rate, and remember to uncheck the “Keep old price” option if you want the price to reflect the new rate :)

Thx for this question. I was also testing this out and now I have the solution

Thank you for the response!

How about when the guest is due to check out and we need to make a correction on the previous night room rate that was not updated when the guest extended.  Is there a way to correct a room rate that has already been posted?

Thank you in advance! 

Hi ​@ramirezramosn and sorry for the slow reply :)

Go into Manage booking > Pricing tab and look for “Set rate excluding products (nightly)” then you can make precise adjustments to the nights, so long it is not outside the editable window period for your property.

Or you can adjust the average nightly rate by a fixed amount or percentage