how to restore keyboard on android - to enter locked screen password
The solution suggested by @Firelord worked perfectly.
I had to purchase a micro-USB to Female USB OTG cable to resolve my issue. The micro-USB end connects to the phone (where the power cable connects) and connect a keyboard into the female usb end.

Power cycle the phone (for the phone to recognize the keyboard ) and just enter the password using the keyboard.

I had struggled with this - installing adb and figuring out how to sideload (manually install) keyboard apps and all kinds of other suggestions from various sites.

I was just moments away from wiping my phone when I remembered Stackexchange.

Thanks everyone for helping out.
Greatly appreciated.