Reading values of Form Input fields - Radio value not available

I can read the value of a form field by doing {{field_name.value}} for instance.

That is great for most fields, but I want to use the selected value of a radio group (or better still, the label) but everything I try results in a [blank].

It doesn’t even show in DevTools when I type
dmx.app.data.dg_admin.report_AD_new.form_new_ad_report.inp_veh_odom_unit
in the Console.

Other fields, such as text fields or select fields do show correctly.

Help.