Optional additional list checkbox for user

[niklasfjeldberg]

It would be nice to have a checkbox where the user can choose to subscribe to an additional list.

The Sendy API (https://sendy.co/api) says it's possible to add a user to multiply lists at once.

[mauryaratan]

@lushkant Can you take on this one?

We simply need to loop through the lists and subscribe the user to specific lists.

embed-sendy/embed-sendy.php

Lines 549 to 550 in 88c23e7

	self::$sendy_api->setListId( filter_var( wp_unslash( $_POST['list'] ) ) );
	$response = self::$sendy_api->subscribe( $data );

• Shortcode attribute should take multiple lists separated by a comma
• Alter the same behavior for Gutenberg Block
• Tweak front-end form to display each list by name, along with a checkbox
• See if we can safely include Add the "Checkbox hack" for a better custom form #18 without creating a conflict between different themes

Let me know if you have any questions or need any clarification.