If you have never had filler, asking about the FDA first is a smart move. Here is what the FDA's own page says.
What the FDA page says about lips
A dermal fillers page at www.fda.gov includes this line: "Augmentation (increased volume) of lips, cheeks, chin, and back of the hand."
Lips appear in that description. That is the plainest answer the FDA page gives. It does not tell you which product suits you or whether you are a good candidate.
The cheap, simple next step
Reading the source costs nothing. Open the FDA's own dermal filler page and see the wording for yourself. For more background, try the ASDS injectables overview and Cleveland Clinic's tear trough filler article, which looks at filler in another part of the face.
Write down what you still do not understand. A list of questions makes a first consultation far more useful.
What is not a do-it-yourself matter
Choosing a product, a dose and an injector is not a home decision or a web-search decision. It belongs with a licensed clinician who can examine you.
Put your FDA question to one directly. A good clinician will not mind a beginner asking it.