How can a marriage contract be completed for a girl in a foreign country, far from her guardian who is in his home country?

Therefore, the guardian's permission is a condition for the validity of the marriage contract, based on the Prophet's (peace be upon him) saying: "Any woman who marries without the permission of her guardian, her marriage is invalid," and his saying: "There is no marriage except with a guardian and two just witnesses." Thus, it is not religiously permissible to complete a marriage contract for a girl except after her guardian's approval. If the girl and the guardian are in different countries, the guardian can authorize someone he trusts to complete the contract.