Does the absence of the girl's guardian (her brother) at the marriage contract affect the legitimacy of the contract, despite his implicit approval and inability to attend?

A girl is given in marriage by her guardian (wali), and the marriage is not valid without his permission. The brother is the guardian of his sister. Efforts should be made to convince him to agree to the marriage. He is not permitted to prevent her from marrying a suitable man without a legitimate Shar'i justification. If he refuses without an acceptable reason, the girl can refer the matter to the authorities responsible for Muslim affairs to arrange her marriage, should they confirm that her guardian is preventing her marriage (adal).

If there is a guardian with more priority than her brother, such as her father, communication can be made with him to delegate someone to marry his daughter. If marriage to her is not feasible, then one can look for someone else.