no controller will connect and sync button on console will not work

Is the controller new? has it been working before?

Try to press the sync button on the controller and the Xbox console. More details can be found here on connecting your wireless controller to Xbox consoles:

https://beta.support.xbox.com/help/hardware-network/controller/connect-a-wireless-controller

I bought it used froma friend he had it working on his console but when I got it the sync button was pushed in all the way. Then I opened up the contoller to find the sync button has completely broken off and rattles around in my contoller so pressing the
sync button on my controller is not possible

Hi and thanks for reaching out. I hope you’re doing well. I'm an Independent Advisor and a Microsoft user like you and I'll be happy to help you.

It sounds like you may have encountered a problem with your Xbox One controller and your console. If the sync button on your controller is not working, you may need to try a few different troubleshooting steps to get it to connect to your console. One thing you can try is to reset the controller by removing the batteries, then pressing and holding the sync button on the controller for about 3 seconds, and then reinserting the batteries and pressing the sync button again. This will put the controller into pairing mode, and you should be able to connect it to your console.

If that doesn't work, you can try connecting the controller to your console using a USB cable. This should allow you to sync the controller to your console, even if the sync button is not working.

If none of these options work, it's possible that the controller is damaged and will need to be repaired or replaced.

connect the controller to the console with a USB cable, turn controller on hit the sync button. The controller should sync to the console and you can then disconnect the USB cable. If it doesn't work on one USB port try a different one.

Restart the console Connect the controller again using the console and the connection button on the controller then it should work.

I already tried the sync button on the remote but nothing( it only keeps on flashing,slowly)

I will try it again

While the controller is flashing, press the sync button on both the controller and console to re-sync the connection. Try this while the controller is wired to the console with a USB cord.