"Do you want to ask him if he can wait for me?"
Translation:Voulez-vous lui demander s'il peut m'attendre ?
Yes, that is correct. What the French call "indirect pronouns" are all pronouns used as object of a verb or phrase using the preposition "à".
Only 3rd person indirect pronouns are different from their direct form: "me, te, lui (il and elle), nous, vous, leur (ils and elles)."
Reminder: with other prepositions (de, avec, sans, devant, après...), the form of the pronoun is the "stressed" one: "moi, toi, lui, elle, soi (on), nous, vous, eux, elles".