Hello Rob115,
Welcome to the Community page,
We do not support corporation tax in Quickbooks, you can manually calculate the corporation tax amount from your profit. Then do a journal from the retained earnings account to a corporation tax liability account. you would have to set this up , then when you pay it to HMRC create an expense and in the category column of the expense select the liability account. We'd recommend speaking with an accountant though to confirm they are with this.