Hello Rob,

thanks for reaching out to us. There is no option right out of the box, but there is a workaround.

For example, you can set the event date to 15/08 and then set the option for booking to open on 31/08.

In that way, customers will not be able to book that event. Then, you can add the hyperlink in the description which will lead to an external website.

I hope it helps. 

Please, let me know if you have any other questions.