  We study a model of the emergent dark universe, which lives on the time-like
hypersurface in a five-dimensional bulk spacetime. The holographic fluid on the
hypersurface is assumed to play the role of the dark sector, mainly including
the dark energy and apparent dark matter. Based on the modified Friedmann
equations, we present a Markov-Chain-Monte-Carlo analysis with the
observational data, including type Ia Supernova and the direct measurement of
the Hubble constant. We obtain a good fitting result and the matter component
turns out to be small enough, which matches well with our theoretical
assumption that only the normal matter is required. After considering the
fitting parameters, an effective potential of the model with a dynamical scalar
field is reconstructed. The parameters in the swampland criteria are extracted,
and they satisfy the criteria at the present epoch but are in tension with the
criteria if the potential is extended to the future direction. The method to
reconstruct the potential is helpful to study the swampland criteria of other
models without an explicit scalar field.
