How I got both the video and audio working in Amazon KVS:

gst-launch-1.0 -v rtspsrc location="rtsp://user:[email protected]/live0" short-header=TRUE name=src src. ! queue ! rtph264depay ! h264parse ! kvssink name=sink stream-name="camera_100" access-key="key" secret-key="secret" aws-region="region" src. ! queue ! rtpmp4gdepay ! aacparse ! sink.

Raspberry Pi 5, Debian GNU/Linux 12 (bookworm)

Kernel: Linux 6.12.47+rpt-rpi-2712 (arm64)