stem of Win Air. You can verify the authenticity of the invoice and the electronic signature by viewing the certificate. To open the file, you need Adobe Reader 9 (or above) installed on your computer. This program can be downloaded free of charge from here. For help with downloading or installing Adobe Reader

tem of Wizz Air. You can verify the authenticity of the invoice and the electronic signature by viewing the certificate. To open the file, you need Adobe Reader 9 (or above) installed on your computer. This program can be downloaded free of charge from here. For help with downloading or installing Adobe Reader