The link in the description is down, and I've tried searching for it elsewhere. The only download links given anywhere are either the down one in the video desc, or to to ukudaily.com, which is also dead.
Did a bit of hunting, but unfortunately the original PDF was available through an online store (albeit free of charge), so although you can access the link on the Wayback Machine you can’t get the PDF any longer. It’s by Tom Guy of Bluegrass Ukes, searching for which led to me to this:
Free Interactive Chords for Rainbow Connection Tom Guy bluegrass Ukes are : Rainbow Connection Tom Guy bluegrass Ukes - Guitar, Piano & Ukulele | Transpose & MIDI
guitaa.com
Hopefully that’s of some help until someone can find the PDF, but it’s not really a proper substitute. Sadly The Wayback Machine crawl of Ukudaily.com has practically every page relating to the tab… but the tab itself is absent.