iPhone 6 stuck on restore

See this for troubleshooting steps, If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support

What do you mean, link doesn't work? You cannot open the link, or the steps in the link don't help? I was able to get the support document link to open. If you are saying the steps did not work, re-read the final step.

Get more help

If you can’t update or restore your device with recovery mode, or you can't use recovery mode because of broken buttons, contact Apple Support.