Hello!
How can I configure Back to home between two mikrotik devices.
Both devices over NAT and cannot receive incoming connnection.

Use BTH.


https://help.mikrotik.com/docs/display/ROS/Back+To+Home

https://www.youtube.com/watch?v=cR6NYBxAMp8&t=139s

Not helpful, anav!

Currently BTH is only meant for Phone or PC connecting to a MikroTik router. There is no option for router-router communication. You can use ZeroTier for this, if you have an ARM device.

Not helpful, anav!

Currently BTH is only meant for Phone or PC connecting to a MikroTik router. There is no option for router-router communication. You can use ZeroTier for this, if you have an ARM device.

Thanks fo reply!
Both mikrotik devices must be ARM???
Is zeroTier free for usage?

Yes, all devices involved need the zerotier package, it only exists for MikroTik "ARM" powered routers. It's free to use:
https://help.mikrotik.com/docs/display/ROS/ZeroTier

Regular wireguard is also an option, if at least one of both devices has a public available IP address (no CGNAT, doesn't have to be static).

holvoetn! OP clearly says both devices do not have public IP ...

My bad Normis, I had never grasped this shortcoming.
Why have you not programmed in both punching through CGNAT for example?
Is this a future development or not possible?

In this case one option is to rent a cloud server and put a CHR on it for example as the wireguard server, to act as the go between for the routers.

Ok. Thanks fo help.!

I think @Normis' suggestion sounds good, i.e., if you have Arm-based devices, you’re able to install ZeroTier (which can cope with CG-NAT) directly on the routers. Alternatively, you might use a computer on each network to act as a hub and install ZeroTier, TailScale, or similar software.