Which ports must be open for HeidiSQL on a Windows machine to connect to a Postgres database on a Linux server:

I have installed HeidiSQL on my Windows desktop. I want my Windows machine to connect to a Linux server with Postgres. On the Windows and Linux machines, there are no firewall rules on ports 5432. The network connectivity between them is out of my control.

I have a question for my troubleshooting efforts.

Which of these are necessary for HeidiSQL on a Windows machine to connect to a Postgres database on a Linux server:

1. Inbound port 5432 must be open to the Linux server
2. Outbound port 5432 must be open from the Linux server
3. Inbound port 5432 must be open to the Windows server
4. Outbound port 5432 must be open from the Windows server

SSH does not require port 22 be opened bidirectionally on each machine engaged in an SSH connection. I want to know the minimum port openings. I may ask my network team for an exception. But I must do my homework first.