“Do You Happen to Have…?” Softens a Request

“Do you happen to have a spare charger?” is a natural, polite question. It still means “Do you have a spare charger?”, but happen to retains a sense of chance and lowers the speaker’s expectation: you may not have one, and that is fine. Cambridge Dictionary lists this structure as a polite way of asking a question.

A: Do you happen to have a pen?
B: Sure—here you go.

“Do you have a pen?” is completely correct, but more neutral. “Have you a pen?” is understandable, yet less natural in everyday Australian conversation. If the other person would need to make an effort to look for the item, an indirect sentence does not remove the imposition. Adding “No worries if not” makes the easy way out explicit.

https://dictionary.cambridge.org/dictionary/english/happen-to