Qualify as a freelancer in a recognised liberal profession and provide the professional licences or qualifications required for the activity.
Show sufficient funds to finance the projects, client or project evidence, and the ability to cover living costs.
Provide identity, accommodation, health-insurance, and, where applicable, pension-provision evidence; applicants over 45 have additional pension requirements.
This is the liberal-profession freelance route, separate from establishing a commercial business.
It should not be presented as a general remote-worker visa.