index.js

let myLeads=[]
const inputEl=document.getElementById("input-el")
const inputBtn=document.getElementById("input-btn")
const ulEl=document.getElementById("ul-el")
const deleteBtn=document.getElementById("delete-btn")
const leadsFromLocalStorage= JSON.parse(localStorage.getItem("myLeads"))
const saveTab= document.getElementById("save-tab")

if(leadsFromLocalStorage){
    myLeads=leadsFromLocalStorage
    render(myLeads)
}

saveTab.addEventListener("click",function(){

    chrome.tabs.query({active: true, currentWindow: true}, function(tabs){
        myLeads.push(tabs[0].url)
        localStorage.setItem("myLeads",JSON.stringify(myLeads))
        render(myLeads)
    })
})

function render(leads){
    let listItems=""
    for(let i=0; i < leads.length; i++)
    {
       listItems +=`
            <li>
                <a target='_blank' href='${leads[i]}'>
                    ${leads[i]} 
                </a>
            </li>
        `
    }
    ulEl.innerHTML=listItems
}

deleteBtn.addEventListener('dblclick',function(){
    localStorage.clear()
    myLeads=[]
    render(myLeads)
    
})

inputBtn.addEventListener("click",function(){
    myLeads.push(inputEl.value)
    inputEl.value=""
    localStorage.setItem("myLeads",JSON.stringify(myLeads))
    render(myLeads)
})