You can pass plugin options as data attributes for adding in directly js selector. Please check plugin docs for more information.
Plugin Docs
<select class="select2" name="states[]" multiple="multiple">
<option value="AL">Alabama</option>
<option value="WY">Wyoming</option>
<option value="LH">Lahore</option>
<option value="KA">Karachi</option>
</select>