content.js

const showToast = (message) => {
   //append html element to webpage
    let toastContainer = document.createElement("div");
    toastContainer.innerText = message;
    toastContainer.className = "toast";
    document.body.appendChild(toastContainer);
  
   //remove element after 2 seconds
    setTimeout(()=>{
        document.body.removeChild(toastContainer);
    }, 2000);
};

chrome.runtime.onMessage.addListener((request, _, sendResponse) => {
        if("toastMessage" in request){
          showToast(request.toastMessage); 
           sendResponse({status: "OK"});
        }
     else{
           sendResponse({status: "FAIL", 
            message: "toastMessage not provided"});           
        }
});