Before you generate the report, it is necessary to set up the company details which will be used to generate it. You can do it in Property Settings / General / Company Details:

Once they are set up and saved, you can go to Reports / Guests and reservations reports / Guest list:

The guest obligatory data in this report is the following:

Date of birth
Document number
Visa number and Purpose of Stay*
ID Expiry date
Check-in day
Check-out day

* The visa number field should be set up here:

It will be reflected in reservation window in Guest Details tab, above the purpose of stay field.

Once you are sure that all the data is correct, choose the dates and downloaded the report. It will be downloaded in unl format, ready to upload.