I was invited to a project. When I "accept interview" I have to quote the job, but the only option is to provide an hourly rate - either custom or based on my profile rate. How do I submit a fixed-price quote for the job?
This is because the client has created the job post they're inviting you to apply to as hourly. In this case, I would suggest you include your hourly rate but mention to the client in your cover letter that you would prefer to work on this project on a Fixed-Price basis. If they decide to hire you they can create a Fixed-Price offer then.