KDBX 4.x format (Keepass >=2.36) is not supported by keepass2john yet, so there is no known way to extract the hash and crack it. Developed while playing Mythical Prolab from HTB
./keepass4brute-rs <DATABASE.kdbx> <WORDLIST.txt># Basic attack with default settings (uses all CPU cores)
./keepass4brute-rs database.kdbx rockyou.txt
# Specify number of threads
./keepass4brute-rs database.kdbx rockyou.txt --threads 8