Template:Buttontest.js

const element = document.querySelector("body")
    let taskDone = false
   
    // function for show button
    const elementShow = () => {
      element.innerHTML = `
        <button id="done-button" style="background-color : ${!taskDone 
          ? "#4dd432" : "#fd67ad"};" onclick=doneTask()>
          ${!taskDone ? "Done" : "not done yet"}
        </button>
        `
    }
    elementShow()

    // click Done button
    const doneTask = () => {
      taskDone = (taskDone ? false : true)
      elementShow()
    }