How to print message on the mission planner screen with font size of 1 inch?

Hi! Please help me!

Here is the issue:
I need to print a message on the mission planner screen when the payloads are dropped. The message need to have size of 1 inch. How do I do that? Is there built-in function in the mission planner that allow me to do it? Or do I need to write custom python code? Thank you very very very much!