Hi Sebastian,
The button is not clickable because the
VAT No. field is invalid.
Our website connects to the
VIES website in order to check if a given VAT Number is valid or not.
So, if your VAT Number validates properly on the VIES website, it should work fine on our website as well.
The VIES website experience some outages from time to time and I guess this has been the issue.
I just tried to purchase a subscription via our website, by using your VAT No, and it was validated properly.
So just try again - when you enter your VAT No. click somewhere on the page so the input is not focused. That's how it will send a request to the VIES website.
Then wait for 2-3 seconds and the field should get validated (it should not be in red).
P.S. I just deleted this invoice so you can use the promo code again.