By Frank Dalleres Gareth Southgate has urged his England team to justify their world-class billing when they take on Denmark in their second Group C game at Euro 2024 on Thursday. England began their campaign with an unconvincing win over Serbia on Sunday and can clinch a place in the last 16 by taking another three points against Denmark in Frankfurt. Southgate’s team beat the Danes to reach the final of the last Euros and opposing goalkeeper Kasper Schmeichel believes the Three Lions have only got stronger. “We have to prove that,” said the England head coach. “Obviously, the opponent is not…