What is the legitimate Islamic solution to secure Mudarabah funds in trade, especially with the recurring claims of loss by partners, in order to avoid Riba and guarantee the capital?

This world is a place of trial, where a person is tested with both good and evil. Therefore, a Muslim must be patient and content with Allah’s decree, strive to earn lawful sustenance, and protect themselves from the evil eye and envy with remembrances (adhkar). It is recommended to undertake the work oneself if possible, and to seek assistance from people of experience and trustworthiness.

Mudarabah (definition) is a contract that involves profit-sharing, and there is no guarantee of capital in it. It is not permissible to stipulate a guarantee of capital on the agent (mudarib).