Zorin Installation Support

I purchased Zorin OS Ultimate (15) last year and thought I had asked the following question not long after. However, I cannot find that post (it does not appear to exist).

When I received my receipt, it stated:
"Hi John,

Thank you for your order. This email confirms that you have made a purchase for the following items and that payment has been approved. You will receive an order email detailing how to access your purchase shortly.

----------------------------------------------------------------
ORDER RECEIPT

Date: 2019-12-14
Order ID: 0051755545
..."

When I go to "Zorin Installation Support", one of the items that needs to enter is a "Registration Number". The page states:
"Registration Number (You can find this number in the purchase email)". It is not in my "ORDER RECEIPT" and either I never received an email with it, or if it was in the "order email detailing how to access your purchase shortly", then I would have missed it as I probably ignored that email (assuming I got one) as I had already downloaded and installed Zorin Ultimate.

So...

How do I get a Registration Number? I would be grateful if anyone can answer this question.

Hi, I will PM AZorin and point him to this thread.

Hi, I will PM AZorin and point him to this thread.

Thank you. Your assistance is greatly appreciated.

I have PM'd AZorin but be mindful it might be a while before I/You get a response.

Hi JRG! We've just now re-sent the email with your download link and Registration Number to your email address.

Hi JRG! We've just now re-sent the email with your download link and Registration Number to your email address.

Thank you, it has been received.