I am trying to send an http request from my pod to the outside, but it seems impossible. I currently have implemented a loadbalancer with fixed IP, but so far I just tested connections to the service.
Is there any specific constraint for it? Is it possible to overcome the issue?
Your worker nodes where your pods live are probably in private subnets (it's good practice to keep them there) and if that is the case then it's not Kubernetes problem. You should setup NAT to allow outbound traffic. I'm not familiar with Azure, but you should also check other abstractions that control your traffic (like Security Group or NACLs in AWS)