Hi all,
one question.
I am using Mikrotik RouterBOARD 941-2nD (6.44.1) and i want to buy a better router Mikrotik hAP ax³.
Can i make a config backup on my old router and restore it on my new router?
Thanks. 
The .backup files are only intended to backup and restore the configuration on the same router. Mikrotik advise against restoring them even on the same model, let alone a completely different one.
Create a .rsc with /export (or /export show-sensitive on RouterOS v7) on the existing device, this is a text file containing the configuration commands. Reset the new device specifying no default configuration, connect with Winbox to its MAC address, post sections of the old configuration in - some commands and parameters may be different between models and/or RouterOS versions so require adjusting. User accounts and any certificates will need to be created separately.
At least wireless config can’t be applied in any of two mentiobed ways. hAP ax3 runs wifi-qcom driver while your old hAP lite runs wireless driver … and configuration of both is completely different.