Mutate changeset field value with ember-bootstrap custom element

I'm on Ember 3.15 (Octane). With the following setup

template

<MyComponent
  @changeset=
  @onSubmit=
/>

component

<BsForm 
  @model=
  @formLayout="horizontal"
  as |form|>

  <form.element
    @label="My Custom Field"
    @property="myField" as |el|>

    <BsButtonGroup
      @value=""
      @type="radio"
      as |bg|>

            // options is a string array ['first', 'second', 'third']
        <bg.button
          @type="info"
          @value=""
          @onChange="" >
          
        </bg.button>
      

    </BsButtonGroup>
  </form.element>
</BsForm>

The problem I'm facing is that the changeset-set is not changing the value of myField when I change the radio button selection. I initially tried @onChange="" but that didn't work.