Crusade in Jeans (2006) on Netflix

Plot summary

In Rotterdam, Dolf's mother, Mary Vega, works at a research center where a time machine can send a person to a chosen time and place and bring them back only from a set spot at a set time. Dolf, fifteen, plays for the junior national football team and has missed the chance to equalize a championship match in Speyer. He plans to travel one day into the past to replay it. He knows the lab and his mother's password, but the guards are alerted, and in his haste he enters the password instead of a destination date. He arrives in 1212 near Speyer and is rescued from vagabonds by Jenne. He joins the Children's Crusade, thousands of children walking from Germany toward Jerusalem under Nicolaas, a boy who has visions, and Father Anselmus, whose route leads to Genoa.