The Swedish version of this site is authoritative if this translation differs from it.
Is the test digital or on paper?
The test is conducted in a test venue under supervision. Whether you answer on screen or on paper is stated in UHR's information and your summons (kallelse).
This question depends on information the authorities have not yet published. We'll update the page as soon as there's news.
Regardless of format, the test is not taken from home. It is a supervised test in a venue, for the same reasons as other tests with legal effect: your identity must be verifiable.
If you see a site offering to let you take 'the official citizenship test online' — that is not the real test.