If {{ip}} might be an Ansible group name, rather than a thing you can SSH
to, then you can't SSH to {{ip}}.
Backing up a step, what are you trying to do here? if you want to run a
command on a bunch of hosts, Ansible will already SSH to those hosts from
your control host to run the command, so you may just need
shell: {{command}}
for your task.
And, if you just want to run a command that you specify on the command
line, you can use the ad-hoc 'ansible' command for that, rather than a
playbook, e.g.
ansible group_domain -m shell -a 'netstat -an | grep 8080'
If you leave off the '-m shell' part, it uses the 'command' module by
default, so you can do stuff like
ansible group_domain -a 'free -m'
if you don't have pipelines or other stuff that requires the 'shell' module.