What is OKTO app? Who can open an OKTO account? Is the OKTO app for free? How do I download the app? What information is required during the registration? How to create your OKTO password? How can I verify my email? How to set a 4-digit PIN security code? Can I deactivate my 4-digit PIN? Can I change my 4-digit PIN? In which languages is the OKTO app available? Can I connect my bank account(s) to my OKTO app?