
To work with Postgre SQL via AL-IV to C# port it is necessary:

1. To have somewhere a Postgre SQL database installed and running;
2. To download and install odbc drivers to connect to the DB (download and install something like psqlodbc_xx_yy_zzzz-xNN.zip);
3. Your application bit depth should mathc the drivers bit depth installed above. Use option /x64 to connect via x64 drivers.
4. Use either DSN=connection created in  Administation\ODBC Connections or directly specify server / database.
Good luck!

Vladimir Kladov. 2021, April, 1.