Just add “dtoverlay=hifiberry-dacplus” to Your config.txt on boot volume. Insert sdcard from RPi to Your computer, find boot volume and edit Your config.txt.
That’s it ! After that now I have :
hassio > hw audio
audio:
input: {}
output:
0,0: 'bcm2835_alsa - bcm2835 ALSA: 0'
0,1: 'bcm2835_alsa - bcm2835 ALSA: 1'
0,2: 'bcm2835_alsa - bcm2835 ALSA: 2'
1,0: 'HifiberryDacp - snd_rpi_hifiberry_dacplus: 0'