PGAdmin

Right Click Servers -> Register -> Server

Complete the details as shown…

Expand the Server Tree - to discover the correct database (gold in colour)

Expand the Schemas -> Tables

General Setting

Register server general setting

Connection Setting

Register server connection setting

Database restoration

Connect database to QGIS

Either use the postgresql connection manager directly, in the browser window, find PostGIS, <right click> and add new connection:

Basic postgresql connection

You can also set up a service file to manage all the connections much more easily:

postgresql-service-connection-file

Warning

Be very cautious when connecting with admin user capabilities, only use this to edit spatial tables within the GIS schema.