why is king charles not allowed to attend the pope's funeral

King Charles is not allowed to attend the Pope's funeral due to royal protocol and precedence which dictate that the Sovereign does not attend funerals. Instead, Prince William attends on behalf of King Charles and the British royal family. This tradition has been followed before; for example, in 2005, then-Prince Charles attended the funeral of Pope John Paul II instead of Queen Elizabeth II. Buckingham Palace has confirmed this protocol as the reason for King Charles' absence from the Vatican for the funeral. Despite not attending the funeral, King Charles paid tribute to Pope Francis and had met him shortly before the Pope's passing.