Export tunnels from SSH Tunnel, file name must end with .json suffix
Open Core Tunnel, click File > Import… from main menu, and select the JSON file
Done
Notes
Core Tunnel will not import a tunnel which its name same as an existing one
Not all the options in SSH Tunnel can be recognized by Core Tunnel, it does not mean Core Tunnel lacks those abilities, but requires you config it manually:
Connect via Interface ➝ Bind Address: you must specify the IP or host name explicitly, e.g. Yangs-MacBook-Pro.local or 10.0.1.2
Connecting through a proxy ➝ use Proxy Jump if the target host must be connected through a bastion server.
Host Key Algorithms ➝ HostKeyAlgorithms in Advanced tab
Key Exchange Algorithms ➝ KexAlgorithms in Advanced tab
Ciphers ➝ Ciphers in Advanced tab
Authentication ➝ in general, you don't need to worry about which authentication method should take, the matched method will be used by Core Tunnel automatically. Consult KbdInteractiveAuthentication, PasswordAuthentication, PubkeyAuthentication and PreferredAuthentications options in Advanced tab if you want to force Core Tunnel use a specified method. For Public Key, you must import the key, or you can install the Helper tool before connecting.