DC doesn't tax nonresidents such as yourself. You would file DC Form D-40B only to get a refund of DC taxes paid or withheld in error. If you didn't have DC taxes withheld or paid then you wouldn't file a DC return at all. The Form would be included in your completed return.
Next time, when TT Personal Info asks if you made money in another state, you would answer No (unless you actually did, but not to DC). That will cause TT to not try to prepare a DC return for you. Hope this helps!