Is it permissible to delegate the slaughter of the Udhiyah (sacrificial animal) on the day of Eid to a butcher in France in exchange for a fee, and will the one who does so be rewarded?

There is no objection to appointing a butcher or anyone whose slaughter is permissible to slaughter the Udhiyah (sacrificial animal). It is not a condition for the sacrificer to slaughter it himself. However, it is preferable for a person to undertake it himself unless there is a predominant benefit in appointing someone. The important thing is that the legal conditions for the Udhiyah are met, such as reaching the prescribed age and being free from defects that prevent its validity, and that the slaughter takes place after the Eid prayer and in accordance with Islamic law.