I lost my remote then I downloaded the remote app but they ask me to enter the code to my Apple TV but I don’t have remote to enter how can I by pass .

Identify your Apple TV model - Apple Support

The Apple TV (2nd or 3rd generation) need a functional remote to set up the Apple TV Remote app.

The Apple TV (4th or 5th generation) should recognize the Apple TV Remote Control Center widget or the Apple TV Remote app, even without a remote.

For the Apple TV (2nd or 3rd generation), your options are:

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