delete_all_tweets.js

var numTweets = parseInt(document.querySelector("[data-count]").innerHTML.replace(/\s+/, ""));

function deleteTweet() {
    document.getElementsByClassName("ProfileTweet-actionButton")[0].click();
    document.getElementsByClassName("js-actionDelete")[0].click();
    document.getElementsByClassName("delete-action")[0].click();
}

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function deleteTweets() {
    for (i = 0; i < numTweets; i++) {
        deleteTweet();
        await sleep(1200);
    }
}