AWS ECS (Fargate) Installation assistance

Hi I am having trouble installing via ECS. I am following the instructions provided. It looks like everything is set up correctly however when I try to open the dashboard I get “This site can’t be reached”

Fargate cluster: existing one setup for company
Security group: exposes all traffic on all ports
Connection string tested locally
Using Json file as advised on docs
Log group: successfully created and the logs only show mapping data and Nest application successfully started.

Any guidance on where to start looking for the problem will be appreciated