if the gym is accredited to do DTV packages they should provide all the docs. It's a letter stating your start date, paid amount, business details. They also provided extra documents of owners passport, business registration and management details etc.
I applied in the evening on 6 Nov, and was approved 12 Nov. Requested on 8th to supply additional docs. That's technically 4 working business days if you exclude the weekend.
Depends what your job title is and if you have a work contract etc.
Partner works remotely on a contract for a company in Australia and the word projwct is in the jon title, and was asked to provide a resume, further documents explaining what the job was, what the projects are, and a portfolio, which isn't entirely relevant as a work contract from employer, and income statements were already supplied. So it seems different for each job and each embassy.