Is it permissible to register a nephew on the ID to obtain a work permit in the absence of children, for the purpose of saving money for an IVF procedure?

The paternal uncle is considered a father, based on the saying of the Prophet (peace be upon him) and the words of Allah Almighty regarding Ishmael's fatherhood to Jacob: "Or were you witnesses when death approached Jacob, when he said to his sons, 'What will you worship after me?' They said, 'We worship your God and the God of your fathers, Abraham, Ishmael, and Isaac — one God. And to Him we are Muslims.'" (Quran 2:133). In this verse, the paternal uncle is referred to as a father. Therefore, there is no harm in you registering the paternal uncle as a parent in official documents, provided you can guard against the risks of adoption, such as the loss or mixing of lineages, the child mixing with non-mahrams, and the loss of inheritance rights.