Kakute H7 ships with Betaflight Firmware.

Kakute H7 V1.5 requires Betaflight version 4.5.2 and newer
Betaflight Target: KAKUTEH7
INAV Target: KAKUTEH7
Ardupilot Target: KakuteH7
PX4: KakuteH7 (PX4 v1.13 or later)Firmware can be built using make holybro_kakuteh7
PX4 Bootloader HEX file for KakuteH7 (v1):

113KB
holybro_kakuteh7_bootloader.hex