I just looked up the "infotainment" manual for a 2020 Silverado and this what I found:
Auxiliary Jack
This vehicle has an auxiliary input
jack. This may be located in the
center stack or center console
under the armrest. Possible auxiliary
audio sources include:
. Laptop computer
. Audio music player
This jack is not an audio output. Do
not plug headphones into the
auxiliary input jack. Set up an
auxiliary device while the vehicle is
in P (Park).
Connect a 3.5mm (1/8 in) cable
from the auxiliary device to the
auxiliary input jack. When a device
is connected, the system can play
audio from the device over the
vehicle speakers.
If an auxiliary device has already
been connected, but a different
source is currently active, press
MEDIA on the center stack or touch
the Media icon on the infotainment
display to scroll through audio
source menus, until the AUX Input
source appears.