foundry/Data/systems/dnd5e/templates/advancement/item-grant-flow.hbs

<form id="{{appId}}" data-level="{{level}}" data-id="{{advancement.id}}" data-type="{{type}}">
  <h3>{{{title}}}</h3>

  {{#each items}}
    <div class="item-name flexrow">
      <div class="item-image" style="background-image: url('{{this.img}}');"></div>
      <label class="flexrow">
        <h4>
          <a data-uuid="{{uuid}}">{{this.name}}</a>
        </h4>
        {{#if @root.optional}}
          <input type="checkbox" name="{{this.uuid}}" {{checked this.checked}}>
        {{else}}
          <input type="hidden" name="{{this.uuid}}" value="true" data-dtype="Boolean">
        {{/if}}
      </label>
    </div>
  {{/each}}
</form>