Login or sign-up to Link4.
After logging-in, select 'Saasu” from the accounting software selection.
Sign in to Saasu and "Select File" (if you are already signed in to Saasu, you will only select "Select the File").
You will now be able to see the customers and suppliers who you have successfully connected with on your dashboard.
Now you can create your invoices from Saasu as usual and Link4 will deliver them to your customers.