JSFiddle - React, Tailwind, and code Playground

JavaScript

var input = "65-KH-ON-PEAK|2.1-K1-ON-PEAK|164-KH-OFF-PEAK|27-K1";
var words = input.split("|");
var ids = [];
for( var i = 0; i < words.length; ++i) {
  var w = words[i];
  var digits = w.match(/[0-9.]+/);
  ids.push(digits[0]);
}

console.log(ids);