Is that an iPhone or Android device. The first thing to check and be absolutely certain of is that the phone is in fact connected to you local network. Have you verified this beyond any doubt? Please don't take the question amiss but it would be silly to start looking for other causes before covering the most obvious
My AMCREST Cameras:-
2 x IP3M-941B firmware V2.620.00AC00.3.R, Build Date: 2019-12-18
1 x IP2M-841B firmware V2.420.AC00.18.R, Build Date: 2019-08-03
Well that clears the basic question up and as I only have a 'normal' doorbell I don't think I can help further. Perhaps someone else will chip in with further thoughts.
My AMCREST Cameras:-
2 x IP3M-941B firmware V2.620.00AC00.3.R, Build Date: 2019-12-18
1 x IP2M-841B firmware V2.420.AC00.18.R, Build Date: 2019-08-03
What needs to happen when you make a connection to your normal Wifi you want to use for your connection on your phone, you bring up the app, you add the camera, and while you add the camera you will be required to make a connection to the Doorbell cameras Hotsport, this will be just like connections to your normal wifi for your phone. I should ask you in a few seconds if you want to connect to a ASH-xyzxxxxxxx, once you make this connection it will then have you finish the setup by adding a new password and telling the camera what Wifi you want it connected to.. When I first went to setup the AD410 I thought it was trying to connect to my Battery camera or by ash-26 because I was expecting to connect to a DB however it comes up as ASH- So I reset the setup and started over on the second setup attempt I did drop down my Samsung bar to reveal the wifi, I then clicked that and choose my camera for connection, and then did the install
On the Android smartphone launch "Amcrest Smart Home" while being connected to my home WiFi, login and tap on the "+ Add Device" middle button
Reading through this thread again, it strikes me that you should not be connected to your LAN at this point and should instead be connecting your phone to the device Local Hotspot (i.e. Network Connection). That is what the error message "says" to me. Unfortunately I've never had one of these devices so can't confirm this for myself.
It is a completely different scenario but the same principal, I have a Panasonic camera that I can control remotely from my iPhone *BUT* to do so I first have to disconnect my phone from my LAN (home network) and then connect to the camera's Local Hotspot (Network) which is entirely separate from and unconnected to my LAN.
My AMCREST Cameras:-
2 x IP3M-941B firmware V2.620.00AC00.3.R, Build Date: 2019-12-18
1 x IP2M-841B firmware V2.420.AC00.18.R, Build Date: 2019-08-03
So I did a Reset and I had to try a few times to make it work. The odd thing for me was when I would as I have done in the past clicked on the Wifi and then clicked on the Hotspot Device it normally would just keep going however this time it popped up with Not connected to internet want to continue and when I said yes thinking it was talking about me being connected to the Hotspot come to find it it kicks me out of the Hotspot and I error out.. Did this 2 times before the second time just waiting for the box to get filled with my DB SN.. It took a little while and was why I kept going the other route. Then it connected.. So I reset once again. Removed from my App and installed again trying to load the Hotspot manually I am not sure if or when it fails but again I get make sure connected to Hotspot was the error.. Did Retry and waited for the DB to come up in the window where you then press connect and I was able to make the connection with no problem..
Also if there is a Delay from the time you start the Hotspot it might be that the Hotspot has went off in the time delayed.. Also not sure this last time when I changed from 1 Wifi to another if I was having issues because the Speaker was off or on really low and every time I turned on the Hotspot not sure if I was trying to go to fast and turned it off not thinking it was on and that was why it was having issues but I did try after being setup to one of my Wifi to change Wifi and have to go through same setup of connecting to hotspot..
At one point I was even getting an error telling me to connect to my Network even after clicking on the Connect of the DB... I did get it to connect 3 different times now each having an issue or 2 before making it work.. Also first time I setup the Ad410 I thought it was trying to connect to a different device at first because it does come up with ASH SN or Hotspot number and throws me off as well.. Now I have setup enough times I know that it will load in a ASH number..
Edit, I just wish it had a Hotspot button like the AD110 does even then not sure it would help always
So have I got this wrong? In the process described by @Cr4z33, when the "next" button is pressed on the phone, should it (the phone) be connected to the home LAN or the doorbell Local Hotspot. If this is not the issue, then the error message that is being displayed seems to be misleading to me.
My AMCREST Cameras:-
2 x IP3M-941B firmware V2.620.00AC00.3.R, Build Date: 2019-12-18
1 x IP2M-841B firmware V2.420.AC00.18.R, Build Date: 2019-08-03