You can currently only stay longer using a work permit, which is a difficult process and will only last you 6 months. Or. you can make use of a retirement Visa. The retirement Visa only applies if you are over 55 years old. All other options are not possible for Digital Nomads until a proper long stay Visa is released. If you are rich, you may be able to make use of the Investor Visa options, which cost up to 80,000 USD in investment and have a 2-year validity, which is renewable once those 2 years are up. This is cheap when compared to other investment Visas, which can cost $500,000+