Add this shorcode to yourtheme/functions.php or use any code snippets plugin to do

 add_filter('op_allow_send_woo_email',function(){
	
     return  true;
 });
add_filter('op_receipt_use_woo_email',function(){
	
     return  true;
 }); 

function custom_op_add_order_after($order,$order_data){
	
	WC()->mailer()->emails['WC_Email_New_Order']->trigger( $order->get_id(), $order, true );
	WC()->mailer()->customer_invoice( $order );
}
add_action( 'op_add_order_after','custom_op_add_order_after',10,2 );