You add a file named "impact.conf" in the same directory as your "impact-qt.exe" file. In that file you put (using notepad whatever)

addnode=194.135.85.185:22629
addnode=213.32.98.226:22629
addnode=217.77.59.45:22629
addnode=5.189.136.88:22629
addnode=65.156.33.58:22629
addnode=88.99.191.218:22629

should work