You can only enter the UK, if you are a British or Irish National, or if you have residence rights in the UK. Passengers should be quarantined in a government-approved hotel for 10 days. Travellers from Red countries will be required to:
Complete a Passenger Locator Form
Take a (PCR or lateral flow) Covid-19 test before arrival
Book a quarantine hotel package for 10 full days, including 2 Covid-19 tests.
Before departure, check the list of red and non-red countries, as the list can change regularly.