In the navigation panel, go to Monitoring → Query plan management.

In the top-right corner of the page, select the instance.

Click Load and install.

Select the databases to install aqo into.

By default, aqo is installed into the public schema. To select a different schema, click the public schema name, select the schema, and click Save.

(Optional) Enable the Enable extension after installation checkbox.

Since aqo version 1.0 cannot be disabled, this checkbox is not displayed for it.

Click Install.