Under current government restrictions operating in England, members of the public, and staff in public facing areas, are required to wear face coverings in theatres and other indoor settings and this applies to the Broadway.
Full details can be found on the government website here.
Face coverings don't have to be worn in hospitality settings, including the Broadway's foyer/bar. However they must be worn before entering the auditorium and remain on whilst seated.
There are various exemptions such as children under 11 years old and people with various medical conditions (again, please follow the above link to the government website for details). So if someone sitting in the auditorium near you isn't wearing a mask, please remember they may have very valid reasons for not doing so.
We hope hope these rule changes will not spoil your enjoyment of shows at the Broadway.