Panasonic AV-HS410, Chroma key change sound output

[ray rush]

i have Panasonic AV-HS410, i’m trying to use chrome key (greenscreen),
SDI 1 from camera (person with green screen)
SDI 2 from PC (adobe premiere)

chroma key work fine,
but it sent false sound output, it sent sound output from PC,
i want to change it to sound output from camera (because someone speak in the news),
how can i change it?

thanks for the help.