<input type="text" name="phone" id="phone" placeholder="+7 (___) ___ - __ - __" inputmode="numeric" autocomplete="off" required="">

$('[name=phone]').mask('+7 (999) 999-99-99');

$("[name=phone]").click(function(){
  var emptyPhone = $("[name=phone]").val();
  if(emptyPhone.lenght=='4'){
     $(this).setCursorPosition(4);
  }
   
  
  
}).mask("+7 (999) 999-99-99", {autoclear: false});


$.fn.setCursorPosition = function(pos) {
  if ($(this).get(0).setSelectionRange) {
    $(this).get(0).setSelectionRange(pos, pos);
  } else if ($(this).get(0).createTextRange) {
    var range = $(this).get(0).createTextRange();
    range.collapse(true);
    range.moveEnd('character', pos);
    range.moveStart('character', pos);
    range.select();
  }
};