s2021,
Look at the ingredients. If there is no sign of milk, then it might just be dairy equipment, as the OU does not use a “DE” designation.
If you see no milk ingredients, you should call them (the OU) at 212-613-8241 and ask. They will tell you if it’s DE vs Dairy if you ask.
Like Daas Yochid said, you can also be matir neder.
Hatzlaha