I'm unclear where you're redirecting from. If you're looking to redirect from Instagram profile pages to Piokok profile pages, then you'd want something like:
Example URL: https://www.instagram.com/linustorvalds
Include Pattern: https://www.instagram.com/*
Redirect to: https://www.piokok.com/profile$1
Choose Wildcard
Description: Redirect instagram profiles to Piokok profiles
Edit: for some reason I can't seem to remove the trailing / from www.instagram.com* You don't want the last backslash in that line. Nothing inbetween com*.
I see the problem: [anything] after the website domain is redirected to profile/[anything]. Imagine running that redirect repeatedly. It will keep on adding "profile" to the beginning. To stop it, you have to make sure the URL after the domain doesn't start with "profile", otherwise you're in danger of a loop.