ECS Service cannot connect to another service with "Service connect"

I have created a service for Redis that I want to connect to it. In order to do so, I added the "Service Connect" feature (see image), nonetheless, I cannot manage to connect to it, not even from the ec2 where it is. I have tried using:

• nc -vz redis-discovery 6379
• nc -vz tcp://redis-discovery 6379
• nc -vz redis 6379
• nc -vz redis-dns 6379
• nc -vz tcp://redis-dns 6379 and none of them work, I keep getting Ncat: Could not resolve hostname "tcp://redis-dns": Name or service not known. QUITTING.