The organic chemistry in the innermost, infalling envelope of the Class
  0 protostar L483
  Context: The protostellar envelopes, outflow and large-scale chemistry of
Class~0 and Class~I objects have been well-studied, but while previous works
have hinted at or found a few Keplerian disks at the Class~0 stage, it remains
to be seen if their presence in this early stage is the norm. Likewise, while
complex organics have been detected toward some Class~0 objects, their
distribution is unknown as they could reside in the hottest parts of the
envelope, in the emerging disk itself or in other components of the
protostellar system, such as shocked regions related to outflows.
  Aims: In this work, we aim to address two related issues regarding
protostars: when rotationally supported disks form around deeply embedded
protostars and where complex organic molecules reside in such objects.
  Methods: We observed the deeply embedded protostar, L483, using Atacama Large
Millimeter/submillimeter Array (ALMA) Band~7 data from Cycles~1 and 3 with a
high angular resolution down to $\sim$~0.1$^{\prime\prime}$ (20~au) scales.
  Results: We find that the kinematics of CS~$J=7$--$6$ and
H$^{13}$CN~$J=4$--$3$ are best fitted by the velocity profile from infall under
conservation of angular momentum and not by a Keplerian profile. The spatial
extents of the observed complex organics are consistent with an estimated ice
sublimation radius of the envelope at $\sim$~50~au, suggesting that the complex
organics exist in the hot corino of L483.
  Conclusions: We find that L483 does not harbor a Keplerian disk down to at
least $15$~au in radius. Instead, the innermost regions of L483 are undergoing
a rotating collapse. This result highlights that some Class~0 objects contain
only very small disks, or none at all, with the complex organic chemistry
taking place on scales inside the hot corino of the envelope, in a region
larger than the emerging disk.
