Change default checkbox output true false into text

Dear Forum members,

I am in need of help with a small project I am working on. I'm a novice when it comes to working on excel and I think this is quite a basic answer, so sorry if this is a dumb question.

Basically, I have inserted checkboxes into my referral spreadsheet. My customers choose the service they require, in this case a diagnostic service (MRI, CT scan, etc), using the excel referral form and then attached the relevant information relating to the medical scan.

It has become apparent that the customers are not attaching the medical reports on sending their referrals which is causing significant delays in us being able to process the request/ scan.

I would therefore like to add a checkbox to the form. When this checkbox is 'checked' I want a bold red underlined large font to appear in another cell on the excel document stating, ''If you are referring for a diagnostic scan please attached the relevant report''.

I've managed to get the checkbox inserted on the form and linked the checkbox to a cell but when I check the checkbox it shows 'true' and uncheck 'false'. I have no idea how to change the 'true' - checked to ''If you are referring for a diagnostic scan please attached the relevant report'' and the 'false' - unchecked to a blank cell.

Can you help me please?

Kind regards

Sebastian