Kirby

Panel custom field with UIKit component...but how?

Hi folks,
I am pretty new to K3 so maybe I have just missed something.
How do I implement a UIKit component such as:

panel.plugin('my/customfield', {
  fields: {
    customfield: {
      props: {
        label: String,
        status: Boolean,
        help: String
      },
      methods: [
        bingo = (val) => {
           console.log('XXXXX');
        }  
      ],
      template: `<k-toggle-field v-model="status" :help="help"  :label="label" name="status" @input="bingo"/>`
    }
  }
});

Unfortunately the field stays blank except label and help. Even if I give it a try with k-checkboxes-field or k-input type=“Toggle” nothing happens.
Does it take an npm install + run build within the plugin folder before they show up?

Thanks & cheers