functional requirements define what a system is supposed to do and non-functional requirements define how a system is supposed to be.
Wikipedia - Non functional requirements
“The system shall produce yellow rocks” is a functional requirement.
“The system shall be yellow” is a non-functional requirement.
What makes 1 a functional requirement is the download. If the system hid the file format used from the user it would be a implementation detail and so a non-functional requirement. But since it’s part of what the system is expected to do it’s a functional requirement.
2 Seems like a non-functional requirement to be extensible. What the fields should be before or after extension is a functional requirement though since that changes what the system makes.