Is Fajr prayer to be observed at the first sunrise over Shaam, or at the second sunrise over Canada, and are other prayers obligatory during a journey in which the sun has disappeared over the North Pole?

If you prayed Fajr in the Levant after confirming its time had entered, then entered another region and saw the dawn of the same day a second time, you are not obligated to repeat the Fajr prayer because your duty concerning it has been discharged. Allah Almighty has not obligated performing a specific prayer twice. Sheikh Al-Islam Ibn Taymiyyah said: "Whoever performs an act of worship as commanded, to the best of their ability, is not required to repeat it." Sheikh Ibn Uthaymeen was asked about a man who broke his fast after sunset then saw the sun again from an airplane, and he replied that the man was not obligated to resume fasting because he had broken his fast based on valid religious evidence.