Crucial to have ten aisles set up (9)

I believe the answer is:

essential

I'm a little stuck... Click here to teach me more about this clue!

'crucial' is the definition.
(I know that crucial can be written as essential)

'have ten aisles set up' is the wordplay.
'ten aisles' anagrams to 'ESSENTIAL'.
But, I'm unsure how the anagram is indicated.

'to' acts as a link.

Can you help me to learn more?

(Other definitions for essential that I've seen before include "Crucial" , "Vitally important" , "So is certain oil-production" , "must-have item" , "Type of oil" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.