<?php
function give_stripe_custom_payment_meta( $charge_args ) {

	// Sanitize the input posted data to the form.
	$posted_data = give_clean( filter_input_array( INPUT_POST ) );

	//Uncomment the followign line to print the $posted_data array to the error log
	//error_log(print_r($posted_data, TRUE));
	
	//Get form ID
	$form_id =  $posted_data['give-form-id]'];
	
	// Edit form ID number as needed
	if( $form_id=123 ) {
		// Prepare metadata fields list.
		$custom_meta_fields = array(
		'Text Field'     => ! empty( $posted_data['text_field'] ) ? $posted_data['text_field'] : 'undefined',
		'Dropdown Field' => ! empty( $posted_data['dropdown_field'] ) ? $posted_data['dropdown_field'][0] : 'undefined',
		'Donor Comment'  => ! empty( $posted_data['give_comment'] ) ? $posted_data['give_comment'] : '',
		);
		$charge_args['metadata'] = array_merge( $charge_args['metadata'], $custom_meta_fields );

		return $charge_args;
	}
	return;
	
}
add_filter( 'give_stripe_create_intent_args', 'give_stripe_custom_payment_meta', 10 );