Use this code example to change the Question [current] / [total] progress bar text.

add_filter('frm_chat_progress_text', 'frm_chat_change_progress_text', 10, 2);
function frm_chat_change_progress_text( $text, $form ) {
	$target_form_id = 225; // change 225 to your form ID.
	if ( $target_form_id === (int) $form->id ) {
		return '[current] / [total]';
	}
	return $text;
}

Use to code example to show the progress bar text in percent with the % sign appended at the end.

add_filter('frm_chat_progress_text', 'frm_chat_show_percent_sign', 10, 2);
function frm_chat_show_percent_sign( $text, $form ) {
	$target_form_id = 225; // change 225 to your form ID.
	if ( $target_form_id === (int) $form->id ) {
		return '[current show=percent]%';
	}
	return $text;
}