Error when using "fancy dongle" functions

[amvidalrc]

Hello. Im using Debian 10 and I want to use the old "fancy dongle" function.
When enabling it:

; Audio devices are normally not needed when in gateway service. These devices should
; only be set when local monitor or dongle modes are required.
outputAudioDevice = /dev/dsp ; Audio device /dev/null, /dev/dsp1, portaudio, etc
inputAudioDevice = /dev/dsp ; Only used for dongle mode

; Below values are for using this as a local DMR dongle (no ASL needed)
useMicrophone = true ; Use app as just a fancy dongle for DMR
useVox = true ; If using dongle mode (useMicrophone), enable VOX

And executing, I got an alsa error. I think you are looking a unknown alsa device:

M: 2020-03-16 02:31:45.100 Audio In/Out Device: /dev/dsp
I: 2020-03-16 02:31:45.100 Begin reading audio from microphone vox enabled
I: 2020-03-16 02:31:45.100 Open UDP listener on 127.0.0.1:31100
I: 2020-03-16 02:31:45.101 Open USRP on 127.0.0.1:32001
D: 2020-03-16 02:31:45.101 Attempt to init DV3000 in DMR mode
M: 2020-03-16 02:31:45.101 Connecting to DV3000 hardware......
hyper-3.0.2-x86_64.AppImage: simple.c:346: snd_mixer_selem_has_playback_switch: Assertion `elem' failed.

Please, as the source code is not open to the public, can give any kind of workaround?

Thanks in advance.