get posted data from radio button cf7
function wpcf7_cstm_function($contact_form) {
$title = $contact_form->title;
$submission = WPCF7_Submission::get_instance();
if ($submission) {
$posted_data = $submission->get_posted_data();
$txt = isset($posted_data['txt'])?$posted_data['txt']:'';
$text2 = isset($posted_data['txt2'])?$posted_data['txt2']:'';
$radio = isset($posted_data['radio'][0])?$posted_data['radio'][0]:'';
// do something with your data
}
}
add_action("wpcf7_before_send_mail", "wpcf7_cstm_function");