Enquire in the backstreet for jobs (5)
I believe the answer is:
tasks
'for jobs' is the definition.
('task' can be a synonym of 'job')
'enquire in the backstreet' is the wordplay.
'enquire' becomes 'ask' (to enquire is to ask or question).
'in the' indicates putting letters inside.
'backstreet' becomes 'ts' ('st' backwards).
'ask' placed into 'ts' is 'TASKS'.
(Other definitions for tasks that I've seen before include "various jobs" , "Pieces of work" , "Chores, jobs" , "'Jobs, undertakings (5)'" , "Jobs to be done" .)