I forgot my screen time passcode and there is no forgot passcode option coming

I note you are using a device with iOS 12. I believe the support article If you forgot your Screen Time passcode - Apple Support referring to the method you use may be assuming everybody is using iOS 13.4 (I have a special note about that change a few years ago).

If you are running a system prior to iOS 13.4, read this Apple Support document about what to do if you forgot the passcode on your iPhone, or your iPhone is disabled. Click here then select your device type if necessary --> If you forgot your iPhone passcode - Apple Support - Also has links for what to do for an iPad or an iPod touch.

This will erase the device. You can restore your device from a backup but the backup has to date from before you set the forgotten passcode or it too will be restored.