Observations in far-infrared and (sub-)mm wavelengths have found evidence for a non-negligible amount of gas around more than 20 nearby main-sequence stars with debris disks. This gas (mostly CO), located in the outer regions of the systems, is likely to have originated via collisions or evaporation of planetesimals due to dynamical instabilities. Gas detected in the optical range with spectroscopy, located much closer to the star, and attributed to the presence of evaporating bodies, has also been found in these systems, pointing towards exocomets as a possible transportation mechanism for volatiles from the outer regions of planetary systems (beyond the snowline) to the inner regions where rocky planets are located. This mechanism, if proved, could have implications on the origin of water on Earth. I present here the first spectra of debris disks obtained with NIRSpec Fixed Slit in the 3 to 5 micron range at R ~ 2,700 to look for volatiles. These objects are part of a sample of 5 objects with observations scheduled to be completed by early fall 2023.