connectedCallback() {
    super.connectedCallback();
    this.type = 'radio';
  }
Lion-radio can be used inside a lion-radio-group.

<lion-radio-group name="radios">
  <label slot="label">My Radio</label>
  <lion-radio>
    <label slot="label">Male</label>
  </lion-radio>
  <lion-radio>
    <label slot="label">Female</label>
  </lion-radio>
</lion-radio-group>

You can preselect an option by setting marking an lion-radio checked.
  Example:
  <lion-radio checked>

@customElement lion-radio