ON my website. IN my profile ON Linkedin.. "Please check more projects on my website or in my LinkedIn profile."

Some things I would edit in your sentence though, are. Add an out after check, remove the own before website, and change the or to and. Like this. Please check out more projects on my website and on my LinkedIn profile.

On is correct in this case.

on the website is correct.

The answer is on. On is related to surface and electronic devices, for instance: computer, internet, and telephone.