As per the Government Covid-19 guidelines passengers must travel with their own face coverings and abide by the social distancing rules outlined on the Gov.uk website for public transport:

Travel Advice: www.gov.uk/guidance/coronavirus-covid-19-safer-travel-guidance-for-passengers#taxis-and-private-hire-vehicles

Face Coverings Advice: www.gov.uk/guidance/coronavirus-covid-19-safer-travel-guidance-for-passengers#face-coverings