'Pay Now' link in e-mail not working

'Pay Now' link in e-mail not working

Hi,
I have a trial subscription to Zoho One and I'm using Billing to try if it will work for my company. I love the features it offers, however stumbled upon a problem. When I send out an e-mail with an invoice, the 'Pay Now' link directs me to the home page of Zoho Billing. I tried on multiple platforms while logging out to Zoho One. The link itself seems to be oke. Could someone point out to me how to make this link direct to the actual payment page?

Greetings,

Edwin 
Edwin Bicycle Sales