how to redirect web-page to avoid traffic loss in git-book

Usually speaking, WordPress and Shopify all have the plugin to redirect web page for avoiding web traffic loss. Now I was using gitbook, i don't know how to redirect traffic, for example, a webpage in gitbook called http://bit.ly/2FKb1lJ. I want user visit http://bit.ly/2FKb1lJ and being automatically redirected to www.gitbook/newwebpage..

I see there is a plugin called gitbook-plugin-redirect offered in gitbook plugin store. but I don't understand how to use it.

from gitbook-plugin-redirect website. https://www.npmjs.com/package/gitbook-plugin-redirect

it says:

gitbook-plugin-redirect Preprocess your Markdown files, replacing all instances of

!REDIRECT "NEW_PATH" with a redirect to the specified path. The path can be absolute(/new/path), or relative(../new/path) or a URI(http://example.com/new/path).

what does this mean???

is this means I put !REDIRECT "www.gitbook/newwebpage" on http://bit.ly/2FKb1lJ.?????

Or Another idea is gitlab good at redirect page??? (offers some convenience feature for website migration??)
So, i don't need gitbook plugin to redirect page (my gitbook hosted on gitlab)