Arthur started the 0-0 draw with Portugal, a result which meant the hosts won the tournament.
The 17 year-old also started the 2-2 draw with Norway and came on as a substitute in a 3-2 win over Australia. He was the only player in the squad from outside the top two divisions English football.
The bulk of the squad is expected to contest the European Under 19 Championships next season. England won the Euros at this level in 2022 with Posh star Ronnie Edwards in the side.
Arthur is under contract at Posh for next season, but the club are keen to extend and improve that deal.