It would be helpful to know what endpoint you were trying to use. There are no endpoints for the Wizard's Vault dailies* if that is what you are trying to get. The old version, v2/achievements/daily, is a dead endpoint right now. If you're trying to get other dailies, like Daily Strike Missions (v2/achievements/categories/250), those still work.
*There is a Wizard's Vault Daily Objectives category, but it is always the same meta Wizard's Vault: Completionist achievement, not specific daily tasks.