The Innovator visa application process is in two stages.
The first stage requires applicants to secure endorsement from a relevant, 'trusted' organisation following an assessment of your business idea against certain criteria. You will be expected to present a comprehensive business plan detailing all aspects of your business idea, including projections for growth, profit, cashflow and job creation, to demonstrate the business meets the endorsement criteria.
The Home Office has yet to release specific details about which organisations will be approved to endorse innovator applicants.
If you are successful in being endorsed, you can then proceed to apply to the Home Office for the Innovator visa.