Unifi UAP-AC-LR reset consequences?

Hi,

Many many moons ago I setup a Unifi UAP-AC-LR (using the app) for my folks.

Lately it seems to be a bit unstable requiring frequent restarts.

I've come to visit with a view to doing some troubleshooting.

First problem I have is that the AP doesnt recognise what I thought was the username and password.

The only way around this as far as I know it to factory reset it.

When I do this what will the default username and password be for configuring with the iOS app?

Is there anything else I should be aware of?

Thanks.