Default sink (Destino padrão) is set to use Bluetooth headphones bluez_sink.64_68_76_AA_11_5C.a2dp_sink
To change default-sink to Onboard Audio:
pactl set-default-sink alsa_output.pci-0000_00_1f.3.analog-stereo
To change audio levels Onboard Audio without changing default-sink
pactl set-sink-volume alsa_output.pci-0000_00_1f.3.analog-stereo +10%
pactl set-sink-volume alsa_output.pci-0000_00_1f.3.analog-stereo -10%
For i3wm it may be simpler to use pulsemixer CLI mixer