It’s claimed all over the Internet, here for example, that below works.
ssh -J username@host1:port username@host2:port
You’ll get an error like this:
Bad stdio forwarding specification 'username@host2:port:22' ssh_exchange_identification: Connection closed by remote host
You have to specify the destination host port with the -p option.
ssh -pdestination_host_port -J username@jumphost:port username@destination_host