Your video is not public, so most people won't be able to see it. That said, no such stuff isn't a plug-in or a snap of the finger, it's typically meticulous animation of shape layer paths/ mask paths with strokes. At the end of the day just another variation on "growing vines" and "organic logo reaveal" stuff as it was popular 15 years ago. That's why you can find plenty of tutorials on this explaining all soprts of techniques and tricks such as creating teh handwriting first in Illustrator and importing/ pasting the masks into AE or applying the strokes and animating their parameters along with animating the masks for jiggly organic looks. Again, barely any plug-in or other fancies required, just a lot of basic keyframe animation and understanding the process.