Is it possible to route an element using path in pure javascript?

Question

JavaScript

There is a svg in which the path / route is built through path d
And for a day now I can’t understand how simple and without problems and convas to make it follow the element I need. I ask for help because there are no solutions on the network, either complex or incomprehensible

Example: There is a svg path curve, using svg.getTotalLength() I get its length 6000 and this is 100%
And for example I need to move the object by 20%, that is, the element must retreat by 1200 pixels along the way
The svg itself has a viewbox 0 0 1920 8900
and the resolution on which I'm testing is 1222

var svg = document.querySelector('.teams')
var x = svg.getPointAtLength(1200).x;
var y = svg.getPointAtLength(1200).y;

document.querySelector('.star').setAttribute('y', y)
document.querySelector('.star').setAttribute('x', x)

I get x - 1570, and y - 6100
values ​​are somehow hellishly large, provided that the parent element of this svg is 1222x4600

How can I make a simple rendering of an element on the route by setting the desired variable?
Maybe there are libraries with examples. I tried motion.js and everyone is trying to position the element through the usual transform relative to the entire page, when, as the route itself, I give huge values, so I suspect because of the viewbox. And what will it give if wrapped in convas and how it will look. Please help, hands down, but the task is interesting