Hi @ostorezio,
to show all your variables you have to explicity model an entry for every property in your form and set the entry to “read-only”. In the examples the forms were created as html-forms. You can find them here:
yourCamundaFolder > server > tomcat > webapps > camunda-invoice > forms
If you want to model your forms with the Camunda Modeler instead, you can model a User-Task and specify every entry you want to be visible in the “Forms”-section on the right side.
Check this link to the docs to see all the constraints you can set for your entries, there you can also set your entries to read-only.
Hope that helps
Regards
Michael