Here are the commands you’ll need to harden SSH on your Mikrotik Routers. It looks like it still can use SSH-RSA, but it does get rid of most of the weaker crytpo algorithms.

/ip/ssh/set strong-crypto=yes allow-none-crypto=no always-allow-password-login=no host-key-size=4096

We’ll want to regenerate the Host Key now that the settings have been changed.

/ip/ssh/regenerate-host-key

It will prompt to enter [y/N] to confirm that you actually want to regenerate the host key. Hit y

After your done, you can use something like ssh-audit to check your equipment.
https://www.ssh-audit.com/

Further hardening information is available at the following link.
https://wiki.mikrotik.com/wiki/Manual:Securing_Your_Router