At the moment I have to do Ctrl + C and Ctrl + V to insert the letter. How can I solve the problem?
Probably the keyboard is broken. Since they probably have to be replaced anyway, you can also carefully lift off the key cap and see if a crumb or coffee stain prevents contact. If cleaning helps, that would be great, but an exchange may be necessary. Keyboards are subject to heavy mechanical stress.
Well there are only two options. Either repair or you have to swap the whole keyboard.
I do not know what exactly is broken. That's why I can't tell you if you can fix that
1. Exchange keyboard.
2. Use external keyboard
3. Use Key Gen and define a key other than P.
4. Use the keyboard screen.