shī fu lái zhī qián xiān wèn qīng chu néng bì miǎn rén lái le cái zhī dào yào shōu fèi de gān gà

师傅来之前先问清楚，能避免“人来了才知道要收费”的尴尬。

Asking the technician clearly before they arrive can avoid the awkwardness of only finding out about the service fee after they show up.