with this, look online the string of the array. from 1 to 20 DS18B20 correctly wired you will have the address.
Once that done, you need to insert the address manually of each DS18B20 into codesys DS18B20. If you use more than 1 DS18B20, you have to click on the DS18B20 already existing, ADD new device and add another DS18B20.