I’ve problem with my school net. I tried to connect to my PC via RDP. Connection was unstable. So I decided to buy new router (Mikrotik RB750Gr3). It is the same like original. But my problem wasn’t the router. It was another user and her stupid activity. OK, So the original router is OK and I made backup. I would like to open this backup in new router and try to use it at my LAN. Only for trial, 'cos in the future maybe will become real problem with oroginal router and I could change them. Is it a bad idea? thx
No better is to export config in txt… (terminal / export) and then apply step by step to new router!
Absolutely do not transfer the backup. Print the setup and enter the values in the TIK manually.
to: ingdaka. thx for your answer
If I understand well I start New terminal from menu and after that I write instruction: “export”. Is it the correct way?
Just run the following command and download the file from the Files section:
/export file=backup-export.rsc
I did it. Now I have that file. And now, how can I “push” it to my other router? 
You can upload the file and import but this is not a good idea as I learned in the past.
Clear the config and copy over the file line by line.
@petrik1 No problem on restoring the .backup on your new router since they are same models…
Just make sure you reset all the MAC addresses through the Interfaces facility… So, you upload the file and click on restore…
In case though you want to import an .rsc file, make sure your router is reset to no-cinfiguration… You can either upload it on your file and import it through terminal or you can even copy-paste the whole configuration on terminal…
I turned on my new router. I used webfix (in work I use to manage my router winbox), files, here I uploaded backup-export.rsc. And now what? thx for advice. 
I tried to impot is by terminal, but when I wrote import backup-export.rsc I got a message Expected end of command. I think I did not give there any argument or parameter
teda presnejšie, že očakáva koniec príkazu na riadku 8 stlpec 34. Takto nižšie vyzerá začiatok konfiguráku
apr/15/2020 14:18:36 by RouterOS 6.40
software id = FCIV-DMPY
model = RouterBOARD 750G r3
serial number = 6F3806813D98
/interface ethernet
set [ find default-name=ether2 ] name=ether2-master
set [ find default-name=ether3 ] master-port=ether2-master
set [ find default-name=ether4 ] master-port=ether2-master
set [ find default-name=ether5 ] master-port=ether2-master
/ip neighbor discovery
set ether1 discover=no
/ip hotspot profile
set [ find default=yes ] html-directory=flash/hotspot
The export you’re trying use is from quite old version of ROS (6.40) and sets some features not available in ROS versions past 6.42, such as this one
set [ find default-name=ether3 ] > master-port=> ether2-master
My suggestion is this: take the new device and start from default config. Then look at the old export and only change or add setting in the new device when you fully understand why it has to be done.
What guys forgot to mention in their replies above is this: imports of exported config work nicely when source and target devices run similar version of ROS. If version numbers are not same at least to the “minor” part[*], then you can run into problems such as this one.
[*] ROS follows version numbering scheme .. … E.g. 6.40.8 … 6 is major, 40 is minor and 8 is revision.
@mkx is right on that…
Or you can upgrade the old device, then take the back up and restore it to the new one…