Attach Email to Ninja Forms Notifications

attachment.php

	public function my_custom_add_attachment( $attachments, $id ) {
		global $ninja_forms_processing;

		// Get our submission ID
		$sub_id = $ninja_forms_processing->get_form_setting( 'sub_id' );

		// convert submission id to array
		$sub_ids = array( $sub_id );

		// File to Attach
		$new_file = [CUSTOM CODE]

		// add new file to attachment array
		$attachments[] = $new_file;

		return $attachments;
	}
	
	add_action( 'nf_email_notification_attachment_types', my_custom_add_attachment, 20 );