Is it permissible to pray in a mosque in a foreign country if its administrators are not trustworthy in managing donation funds, and nothing can be done about them except to supplicate?

If you fulfill the duty of advising, enjoining good, and forbidding evil to the best of your ability, then you have discharged your responsibility. The Friday prayer and congregational prayers are valid behind every righteous and wicked person, and there is no sin upon you for praying behind them. If you do not find another mosque, do not abandon congregational prayer in this mosque due to the corruption of those in charge of it.