If you want to accept all invitations , input this in the console

Linkedin-invitation-accept

If you want to accept all invitations , input this in the console 
This has a delay of 2 Seconds on Every Invitation

var x = document.querySelectorAll('button.artdeco-button--secondary');
for (var i = 0; i < x.length; i++) {
  setTimeout(function(idx) {
    if (x[idx]) {
      x[idx].click();
    }
  }, 2000 * i, i);
}