Making the front camera the main one, or disabling the main (back) camera

My device’s rear (main) camera is broken.

WhatsApp Web pairing uses the main camera in order to scan a QR code and can’t be switched to the front (selfie) one.

Is there any ADB command that can switch the roles of Main and Front cameras? this way, the front will be activated by WhatsApp and I’ll be able to scan the QR code.

Alternatively is there an ADB command that disables the main camera altogether? since that might also do the trick.

I’m with Android 10 with latest security updates (Android One).