[root@freepbx sysconfig]# ssh -p2200 fop2support@support.asternic.net -R2222:localhost:22 -R8000:localhost:80 -R9000:localhost:443 -R4445:localhost:4445
The authenticity of host '[support.asternic.net]:2200 ([149.56.9.48]:2200)' can't be established.
ECDSA key fingerprint is SHA256:OSGlK7rzIhh8HYM9Jlf2ZxvoPJwuInNYKre7IcGZCgA.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
..
basically, tech created a user for customer to login remotely login their own box, then ssh back to root, customer enter root password, connection established