Google doorbel

[Bersaneti]

I bought a house and the previous owner left an intercom. I have no contact with him. Is there any way I can use this Google doorbell?

[MplsCustomer]

@Bersaneti 

You will need to perform a factory reset on your doorbell and then install it in either the Google Nest app or the Google Home app, as appropriate.

I can't tell what doorbell you really have. Your post says "Nest Doorbell battery" and "Nest app (iOS)", but the 2nd gen battery doorbell can only be installed in the Google Home app.

Here are instructions for "Restarts" and "Factory resets":

https://support.google.com/googlenest/answer/9252162