Subscriber created when creating account

When a user creates an account on my site, there are only fields for First Name, Last Name, Email Address and Password. When they submit this information, it is automatically subscribing that user to receive email, even though they haven’t opted in. The option to add a checkbox to ask to be opted in only appears to work on checkout. How do I either add a checkbox to the account creation page or prevent the user from being subscribed?

Hi there, did you ever find a solution to this? I am having the same issue, thanks