Add Automatically Photo & Description of woocommerce product

Hello there

I think you may use the following code as a reference and adapt it to your requirements in order to create the invoices programmatically.

function sliced_create_invoice_programmatically_example() {
	
	/**
	 * 1) Invoices are stored as Custom Post Type 'sliced_invoice'.
	 * Let's start by creating a new post:
	 */
	$args = array(
		'post_title'      => 'Example Invoice Title',
		'post_content'    => 'Description here',
		'post_author'     => get_current_user_id(),
		'post_status'     => 'publish',
		'post_type'       => 'sliced_invoice',
	);
	$invoice_id = wp_insert_post( $args );
	
	/**
	 * 2) now let's attach some extra pieces of information.
	 * These are stored as post metas:
	 */
	// MOST IMPORTANT, the user ID of the client the invoice is associated with:
	update_post_meta( $invoice_id, '_sliced_client', 1 ); // example: user ID "1"
	
	// invoice created date:
	update_post_meta( $invoice_id, '_sliced_invoice_created', time() ); // example: now
	
	// invoice due date:
	update_post_meta( $invoice_id, '_sliced_invoice_due', date( "U", strtotime( "2018-12-31" ) ) ); // example: Dec. 31, 2018
	
	// invoice number:
	update_post_meta( $invoice_id, '_sliced_invoice_number', sliced_get_next_invoice_number() );
	Sliced_Invoice::update_invoice_number( $invoice_id ); // advance invoice number for the next time
	
	// automatically enable your chosen payment methods:
	$payment_methods = sliced_get_accepted_payment_methods();
	update_post_meta( $invoice_id, '_sliced_payment_methods', array_keys($payment_methods) );
	
	// let's put in some line items:
	$line_items = array(
		array( 
			'qty'     => '1',
			'title'   => 'Test item',
			'amount'  => '100',
			'taxable' => 'on', // taxable
		),
		array( 
			'qty'     => '1',
			'title'   => 'Another test item',
			'amount'  => '20',
			'taxable' => false, // not taxable
		),
	);
	update_post_meta( $invoice_id, '_sliced_items', $line_items );
	
	// set status as draft:
	Sliced_Invoice::set_as_draft( $invoice_id );
	
	// anything else you want to add here...
	

	/**
	 * That's it!
	 */
	return $invoice_id;
	
}

// 'init' is a good place to hook into.
// The Sliced Invoices plugin will be fully loaded by this point:
add_action( 'init', 'sliced_create_invoice_programmatically_example' );

My best,
Andrew