If you have not registered on the IntegrityNext platform yet, please contact our support team at: support@integritynext.com. If you prefer to write directly to your customer, you will find their contact details at the end of the invitation email in the signature.
If you are already registered, you don't need an invitation link anymore but you can log in directly in the login area: https://app.integritynext.com/login, and therewith share your existing supplier profile with your customer.