All job applications these days are online. If you can’t fill out the form completely, no one will call you. A resume can be added along with the application. If you can bullet point experience, goals, and previous employment on one page, all the better. Unemployment offices usually can help you condense a resume to the one-page goal. Of all the resumes received, you want yours to be in the small stack of prospective candidates.
As for reasons for leaving, you’ll have to be inventive. Like explaining that your skills and their job requirements were not a good match, and the position was terminated by mutual agreement. Unless there is a termination letter, your word against theirs.
You haven’t mentioned yet your area of expertise, unless I missed that. It might be helpful for those giving advice.