What did the people ask Rehoboam to do?

Answer: Lighten their heavy yoke

The people said Solomon had put a heavy yoke on them and asked Rehoboam to lighten it, promising to serve him.

““Your father put a heavy yoke on us. But now you must lighten the burden of your father’s service and the heavy yoke he put on us, and we will serve you.””— 1 Kings 12:4 (BSB)