That's a generic app, that can be used with all makes of cameras.
If you can remember what the default password was, have you tried entering it?
If you can't remember what the password was then, if you can work out who actually made the camera, you might be able to find the default password here:
https://www.a1securitycameras.com/technical-support/default-username-passwords-ip-addresses-for-surveillance-cameras/
However your friend might well be correct. Websites such as shodan.io continuously scour the internet to find IP addresses which are associated with 'the internet of things'. (i.e. they look for indications that they're being used by security cameras or things like industrial control systems, rather than by computers). Those results are searchable by anyone who subscribes to the site but the IP addresses which they find are still useless to those subscribers unless they know the relevant passwords to go with them.
However, if a default password has been used, it can then be entered by anyone who's curious enough to see what's connected to that IP address, enabling them to take control of it (e.g. by viewing what a camera is showing and/or by changing the password to one of their own).
If you've still got the instruction manual for your camera, see if there's a way of resetting it back to the factory default. That will either restore the password that it came with or remove the password altogether. (In either case you should then be able to create, or change to, a password of your own, so that the problem doesn't happen again).