https://medium.com/@acoyfellow/mass-linkedin-request-without-3rd-party-software-dff998aedd23

MassLinkedInConnect.js

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

async function connect(profile, i) {
  try {
    const a=document.querySelector(`#${profile.id} a`);
    if(a===null){
        run();
        return;
    };
    const url = a.href;
    const connectBtn = document.querySelector(
      `#${profile.id} button[aria-label^='Connect']`
    );
    if (connectBtn === null && profiles && profiles[i + 1]) {
      connect(
        profiles[i + 1],
        i + 1
      );
      return;
    } else if (connectBtn === null) {
      run();
      return;
    }
    connectBtn.click();
    await sleep(2000);
    const addNoteBtn = document.querySelectorAll(
      "button[aria-label^='Add a note']"
    )[0];
    const h2 = document.getElementById("send-invite-modal").innerHTML;
    if (h2.trim() === "Connect") {
      const dismiss = document.querySelector("button[aria-label^='Dismiss']");
      profile.parentNode.removeChild(profile);
      dismiss.click();
      run();
      return;
    }
    if (addNoteBtn === null) {
      run();
      return;
    }
    addNoteBtn.click();
    await sleep(1000);

    const name = document
      .getElementById("send-invite-modal")
      .innerHTML.replace("Invite ", "")
      .replace(" to connect", "")
      .trim();
    const textarea = document.querySelector("#custom-message");
    textarea.value = `Hey ${name}, I'd be honored if we could connect here on LinkedIn :)`;

    const sendInvitationBtn = document.querySelector(
      "button[aria-label^='Send invitation']"
    );

    const http = new XMLHttpRequest();
    http.open("GET", url);
    http.send();
    sendInvitationBtn.click();
    await sleep(2500);
    run();
    console.log('Requested + Profile Visited:', i, name, url);
  } catch (e) {
    console.error(e);
    if (profile) {
      connect(
        profile,
        i
      );
    }
  }
}

var connected = [];
var profiles = [];

async function run() {
  window.scrollTo(0, document.body.scrollHeight);
  await sleep(250);
  profiles = document.querySelectorAll("li.search-result");
  profiles.forEach(profile => {
    const connectBtn = document.querySelector(
      `#${profile.id} button[aria-label^='Connect']`
    );
    if (connectBtn===null) {
      profile.parentNode.removeChild(profile);
    }
  });

  if (profiles.length === 0) {
    console.log("Next Page >");
    const nextPageBtn = document.querySelector("button[aria-label^='Next']");
    nextPageBtn.click();
    await sleep(3500);
    run();
  } else {
    connect(
      profiles[connected.length],
      connected.length
    );
  }
}

run();

This was great! A shame it stopped working. It now tries to hit the connection button on the top left in Linkedin. Anyway to fix?

It seems it stopped submitting the connect text and not clicking the next page.