Your server's reply to an ipn call should be a simple text.To indicate, that the call is successful, just return this response:OKYou may add extra data, e.g.:OK thankyou_url: https://www.some-domain.com/thank-you username: some-user-namepassword: a-secret-password loginurl: https://www.some-domain.com/login headline: You access data"By default the access data are shown in the Digistore24 order confirmation email and on the invoice.To not show the access data on the invoice, add a line:hide_on: invoiceAdding multiple member accountsIf you want to create more than one membership accounts, just add more username/password sets. Append "_2" for the second account, "_3_" for the third and so on. Example:OK thankyou_url: https://...username: some-user-namepassword: a-secret-password loginurl: https://www.some-domain.com/loginusername_2: another-user-namepassword_2: another-passwordloginurl_2: https://another-url.com/loginheadline: You access data"Adding custom dataYou may add any kind of data.The response need to start with OK.You may  add any key-value pairs.Text needs to be plain text and cannot have html tags.OKheadline: Your software Your license key: some-keyYour software package: a package name