i dont think that plugin is the problem itself, as installing it here and using it with the default settings works just fine

in fact, looking at your site at https://www.soledipizza.it you still seem to have that plugin running i cannot see any issue

..?!

the add ingredients plugin has several tabs at the top , one of them is labelled “options” …
that’s where you can find it ( alongside other options)..

> If it’s from a company we’ve used before I don’t mind so much.
sure, and if you’ve opted in to such emails, it’s perfectly legitimate

some related musings on that subject:
https://docs.wp-pizza.com/faqs/?section=force-registration-before-ordering

> $order[customer][ccomments][value]
it’s not me who decides which field you use for comments …
it depends on which field YOU have set in wppizza->form fields to be used for comments (if you hover over the enable button in there [v3.5+] you will see the parameter key)

like elsewhere, the laws exist in most places to deal with that.
the problem – as always – is the enforcement of them….

just making an educated guess here and assuming the restaurant in question is in Australia (I might be wrong on that front of course)
maybe you want to tell your boss this (just saying):

quote:
The penalty units referred to in the Spam Act are equal to $210 each. For example, the penalty under section 25(5)(b) of the Spam Act for a company with a previous record of spamming and who sent two or more spam messages on a given day without consent is a maximum fine of 10,000 penalty units. This equates to a maximum penalty of $2,100,000.

see: https://www.acma.gov.au/Industry/Marketers/Anti-Spam/Ensuring-you-dont-spam/spam-legislation-enforcement-ensuring-you-dont-spam-i-acma

I am sure variations of the above exist for most – if not all – countries

>The restaurant wishes to enable guest checkouts to increase conversion rates whilst maintaining the ability to Remarket email and SMS promotions in the future.

and this would be completely illegal. never mind GDPR (which may or may not apply to that restaurant)
it’s simply called SPAM

I am sure there are plenty of wordpress plugins out there that let you export registered users with whatever data they chose to register

and there’s also the “WordPress -> tools -> export personal data” option (WP 4.9.6+)

really depends how it’s setup in the first place
if you have something (in this case Onions) preselected, the customer can just de-select it
if it is only in your description that an item has onions, then of course th eplugin will not know anything about it
however, you could simply add a “No Onion” topping so to speak a customer can then select (you could also set negative prices
there if you wanted!)

Naturally, the customer can of course also write “no onions” into a textbox

> but now I have just activated.
and i dont see any popup anymore….

…you must define a homepage of some sort in wordpress