How to connect a private server using public server as an jump server/bastion host? 

too fast for a tutorial, you knew what you were doing yet some people who are seeing it for the first time do not, very hard as i had to pause multiple times and play on 0.5 speed, please go slow next time!.. thankyou though!

i did everything you mentioned but when i run the ssh command, it says 'ssh permissin denied"