I currently own a Modbook Pro (a 2012 MacBook Pro turned into a Wacom Style Tablet). Can I please get help with doing a factory reset after I erased the Internal MBP SSD under Disk Utility?

I just went to disk utility tonight on my used Modbook Pro ( a 2012 MacBook Pro turned into a Wacom Style Touch Screen Tablet) and I erased the Internal MBP SSD before I backed anything up on it. Is there any way for me to get a working version of any macOS operating system on it. I was trying to do a factory reset of the Modbook Pro before I sell it on ebay, so the next owner could set it up as their own system from start. Any help will be appreciated.