Cannot add the passcode in Apple TV as have no remote? Any ideas please? Thanks

What is your model Apple TV? Identify your Apple TV model - Apple Support

Also see: Set up the Apple TV Remote on your iPhone, iPad, or iPod touch - Apple Support

The Apple TV (4th generation or later) should be straight-forward to pair with, as described, if both devices are already on the same home network.

The Apple TV (3rd generation) needs a functional remote to help set up the software Apple TV Remote from Control Center.

For the Apple TV (3rd generation), your options are:

• buy a replacement Apple Remote (aluminum);
• temporarily borrow an Apple Remote (aluminum) to help set up the software remote;
• restore the Apple TV and connect a wireless keyboard to help set up the software remote;
• restore the Apple TV and connect the CiderTV Mac app to help set up the software remote.

The Apple TV (2nd generation) is not compatible with the software Apple TV Remote from Control Center.

For the Apple TV (2nd generation), your option is:

• buy a replacement Apple Remote (aluminum).

The Apple TV (1st generation) was never compatible with the software Apple TV Remote on iPhone.

For the Apple TV (1st generation), your option is:

• buy a replacement Apple Remote (aluminum).