Basics of Select2 and Stimulus

select2_controller.js

import { Controller } from "stimulus"
import $ from 'jquery';

require("select2/dist/css/select2")
require("select2-bootstrap-theme/dist/select2-bootstrap")

import Select2 from "select2"


export default class extends Controller {
  connect() {
    $('.subscriber-tags').select2({
      tags: true,
      tokenSeparators: [',', ' ']
    });
  }
}

some_view.html.erb

<%= form_with(model: @my_model, local: true) do |form| %>
  <div class='card mt-4'>
    <div class='card-header'>
      Tags
    </div>
    <div class='card-body' data-controller='select2'>
     <%= form.select :tags, SubscriberTag.all.map{ |t| [t.name,t.id]}, {include_blank: true, required: false, include_hidden: false}, class: 'form-control subscriber-tags', multiple: 'multiple' %>
    </div>
  </div>
<% end %>