There are more or less errors in your question.

First of all, it should be "where to sell fried dough sticks" instead of "where to buy fried dough sticks", or where to buy fried dough sticks in Chengguan Town.

Secondly, the kind you said are wrapped in glutinous rice are not actually called fried dough sticks. The real fried dough sticks are very soft, similar to fried dough cakes, and are eaten by northerners for breakfast.

The ones in Shengzhou that are filled with glutinous rice are technically "old fried dough sticks" and are fried for a longer time.