JSFiddle - React, Tailwind, and code Playground
JavaScript
var str = 'User ID: 2894, Task ID: 68, Some other text'
arr1 = str.split(', ')
arr2 = arr1[1].split(': ')
arr2.splice(1, 1, '<replaced>')
arr1[1] = arr2.join(': ')
str = arr1.join(', ')
console.log(str)