I have a Ring 4 Doorbell. (Yes I’m a slave to Amazon

) It was fitted when I was discharged from hospital so that I could communicate with couriers/district nurse etc when I was hooked up to an antibiotic drip and I couldn’t get to the door.
To set it up on your phone as the account holder you will need to be on the same wi-fi as the doorbell/home wi-fi. Once set up you can view it away from home using 4G or whatever. Also bear in mind your mobile phone Android/iPhone software version, as it requires a later version to run the app. On the Ring Doorbell 4 it requires a minimum of Android version 9 and on iPhone it requires a minimum of version 13 I believe. It conveniently doesn’t mention that on the box as far as I can see.
Proximity and motion sensor are very easy to edit using the drag to boundary feature, so you don’t catch the neighbours in your recordings.
As TB mentioned, the notification takes a few seconds, so I have mine set to ‘Pre-Roll’, which catches the motion before the delivery guy gets to the door. You then have to switch to Live View to speak to them.
Now to everyone’s favourite bit of being an Amazon Slave, to save recordings for a month costs £35 per year. Not a big deal for me but if you don’t subscribe you have no recordings, but Live View still works without subscription.

I probably haven’t answered the original question but, if somebody can set up the phone/doorbell wi-fi at your Dad’s end ’on their phone’, they could send you an ‘invite’ as a guest via the app as an approved person to view the footage and use Live View. This is how my wife views the doorbell on her phone, as a guest of me.

That way your phone wouldn’t need to be in the UK, but obviously I’ve never tried it from abroad myself.