If you have installed the software but the computer does not "see" the t.racks unit:
The t.racks DS 2.4 was heavily sold by the German retailer Thomann. They usually retain legacy drivers for the products they distribute.
Go to the Thomann Music website (since t.racks is their house brand). Search for "t.racks DS 2 4" and look for the "Downloads" tab on the product page. The software is usually called "t.racks FIR Control" or a similar control application for Windows (and sometimes macOS).