If you don't have access to a computer running iTunes, you will have to erase it using Find My iPhone.
I have an iPhone 8 Plus only and I forgot my passcode and now I don’t know how to take it off
2 replies
Mar 2018 - Useful tip on recovering from a disabled state if you have no access to a computer but do have access to another mobile device and a recent backup - https://discussions.apple.com/thread/8302574?answerId=33099578022#33099578022 - Use Find My iPhone app or computer iCloud login to erase diabled device and then restore the device from its backup.
how do i remove my passcode without laptop