Ask them if they have push developers. It's likely to be a vitamin C based one, which is recommended for T-grain films like this. Typical ones would be XTOL, DD-X, Microphen, T-Max, Acufine.
Note the developer they use and check the recommended ISO setting for Delta with that, so you can properly expose the film.
When dropping off the film, write down the developer you want them to use and the ISO setting you shot at.