You will need a remote. The software remote on iPhone, or Apple’s physical remote. It is recommended to have the physical remote ready in case of emergency, even if you regularly use the software remote.
If you can’t make it work, and can’t borrow an Apple TV remote temporarily, then you should buy a replacement remote, or visit an Apple Store or an Apple Authorized Service Provider to let them help you reset the unit.
i-phone remote ask for 4 digit number which I don't remember
The pairing code should appear on-screen if the Apple TV system is running smoothly. The user should be able to watch the screen. The Apple TV box is producing a normal picture, correct? Else the issue is even more serious than described.
but Apple TV does not have a c - connection to reset from the laptop!
Indeed, Apple TV 4K does not have an USB-C port. To restore when the menus are not accessible, you should contact Apple for these models.