Zulu user extension

I have some confusion regarding users , extensions and zulu .

we use FreePBX

My questions:

for zulu should a dedicated extension be used [ i assume so ]

for a user with multiple extensions , is there a way to specify which extension will be used in zulu?

as of my limited zulu know how - it seems that a dedicated extension and user are needed . is that assumption right or not?

so after that I found in Primary Linked Extension in zulu config… I was never going to see that until the post above.