How to connect C port flash drive to iPad Pro 2020?

Hello,

iPadOS supports the following disk formats with a GUID partition scheme:

• macOS Extended journaled — YES Read and Write
• APFS - Coming in iPadOS 14
• FAT32 — SOME*
• exFAT — SOME**
• NTFS — NO

*iPadOS 13 supports solid state devices formatted as FAT32 such as a SD card. iPadOS 13 does not supports mechanical hard disks formatted as FAT32.

** iPadOS 13 supports disks formatted as exFAT as long as it was formatted with Disk Utility on a Macintosh. The disk cannot be formatted by Windows.

Connect external devices or servers with Files on iPad - Apple Support