How to do I add a vignette on my profile, any help would be greatly appreciated!

I've been trying to add a vignette for a long and nothing has been working. I want it to look something like this: https://codepen.io/noracreates/pen/qBKdpaK I know it's for Everskies but I can't find anything else that looks close to how I would like the vignette to look like. Any help with code or anything else be appreciated, thank you :D