In the DNF game, to conduct a single-player team attack, you first need to enter the correct channel. Therefore, at the beginning of the game, you need to switch to the group channel where you need to attack alone.
Next, you need to find the group NPC in the game. Usually, they will appear at the entrance to the instance. After you find them, click the Team Up button.
In the group interface, you also need to click on the single player option. This will allow you to choose solo attack mode.
Finally, click the [OK] button, and you have successfully selected the single-player attack mode. Now, you can start challenging the solo version of the group version.