Unity 2019.4.3f1 does not support Apple Silicon (M1/M2) natively. It runs under Rosetta 2 on Macs. Native ARM64 support began in Unity 2022 LTS.
(Always get the official checksum from Unity鈥檚 archive page under "Verify Downloads" 鈥� this hash is illustrative; do not use for production validation.) unity 2019.4.3f1 download