It looks like you have to “learn” the IR-codes for your specific AC units to be able to control them through the BroadLink RM3s. With Broadlink Manager (Docker) you can do this in a quite convenient way (comprehensive HA thread here).
Depending on the HA install method used you can either install it directly on your HA device or simply use another RPI. After you have learned the codes you don’t need Broadlink Manager anymore.