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()
   }