Generate and Send Invoice Number to Authorize.Net

/*

 * Include an invoice number into the set of Authorize.Net args.

 *

 * @link  https://wpforms.com/developers/how-to-send-an-invoice-number-through-to-authorize-net-payments

 */

function wpf_dev_authorize_net_process_payment_single_add_invoice_to_args( $args, $process ) {

    // Replace 20 in $process->fields[20] to an id of your invoice field.

    if ( isset( $process->fields[20][ 'value' ] ) ) {

        $args[ 'invoice' ] = $process->fields[20][ 'value' ];

    }

    return $args;

}

add_filter( 'wpforms_authorize_net_process_payment_single_args', 'wpf_dev_authorize_net_process_payment_single_add_invoice_to_args', 10, 2 );

/**

 * Set the transaction order invoice number.

 *

 * @link  https://wpforms.com/developers/how-to-send-an-invoice-number-through-to-authorize-net-payments

 */

function wpf_dev_authorize_net_process_transaction_add_invoice_to_transaction( $transaction, $args ) {

    if ( ! isset( $args[ 'invoice' ] ) ) {

        return $transaction;

    }

    $order = $transaction->getOrder();

    if ( is_null( $order ) ) {

        $order = new \net\authorize\api\contract\v1\OrderType();

    }

    $order->setInvoiceNumber( $args[ 'invoice' ] );

    $transaction->setOrder( $order );

    return $transaction;

}

add_filter( 'wpforms_authorize_net_process_transaction', 'wpf_dev_authorize_net_process_transaction_add_invoice_to_transaction', 10, 2 );