Once the fixtures have been added to the patch, it is possible to change their addresses:
In the upper left corner click on the menu icon.

Press the "Patch" button.

Select the top tab “PATCHED".

Select one or more fixtures.

Press the "REPATCH" button, on the right side and a panel will be displayed where you can enter the new DMX address or universe.

Set the new address for the fixtures and press "REPATCH".