No, it is generally not recommended to use landscape fabric under raised garden beds, especially for growing vegetables or deep-rooted plants. The fabric creates a barrier that stops plant roots from growing deep into the native soil, which can stunt their growth and limit their access to moisture and nutrients.
It also blocks beneficial earthworms and microorganisms from traveling up from the subsoil, which is critical for long-term soil health and aeration. The main exception is if you are building over contaminated soil or a patch of aggressive, invasive weeds.
