Mimic header with fading font as you scroll (example in post)

Hi all,

Saw a really cool header today that I would like to mimic. On the website: https://ollysorsby.co.uk/ as you scroll down the header image moves slightly up and the font fades out. I am working on a similar portfolio website right now and would like to do the same with the header (layer slider) image I currently have. My website can be found at: https://chrisneuwirth.com The theme I am using is BeTheme and I am operating the most recent version of wordpress.

Any and all help is greatly appreciated, thanks!