I have an old iPhone once reset and activated with another Apple ID but lost pin to open. I would like to reset the iPhone.
I don’t know Apple ID or pin to open iPhone, but I would like to reset to use again.
It appears that your iPhone is activation locked.
You will need to have the Apple ID and Apple ID Password of the person who originally set up the iPhone to remove the Activation Lock on the device.
If you are original owner and can provide proof of ownership to Apple, you could submit an Unlock Request.
More info here: How to remove Activation Lock - Apple Support