Got it. Here is a solution for if you have a Bluetooth keyboard but no WIRED keyboard.
Step 1: Create a boot drive on a USB Stick, using a different computer.
Step 2. Shut your computer (the one that won’t connect) down by holding the power button down for a few seconds.
Step 3: Disconnect the internal Hard Drive.
Step 4: Insert the bootable USB key.
Step 5: Make sure your Bluetooth Keyboard is near your machine, is not paired with ANY other device and is in Discovery mode.
StepPower on your machine by pressing the power button.
Your machine will boot from the USB drive and after a couple moments, you will get this screen: (pic attached).
After a moment or so of that screen a 6 digit number will appear.
Step 7: Enter that number into your keyboard and it will connect.
Step 8: Shut the machine down.
Step 9. Reconnect your internalHard Drive and remove the USB Stick.
Step 10: Power on your machine and it will boot up connected to your Bluetooth Keyboard.
The end: you do not need a wired keyboard.