Access code

See this link-->If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

There's no way to restore it.

You have to erase your iPhone using iTunes.

Or head to icloud.com, log in with your Apple ID, select your iPhone on the devices list and erase it from there.

Note that all of the data would be lost. So, I hope you backed up your iPhone recently.