Why can’t I do a factory reset on my tablet?

I have tried to factory reset my tablet several times. It’s a Walmart Onn tablet. I have held the power and volume down selected wipe all info factory reset. I have also tried the power button and volume up and got to the Chinese menu try to wipe it that way. When I get to the Home Screen. Hit start it wants me to sign in with my previous gmail account. It has a lock on left top screen, and the Wi-Fi button on. I just want to wipe everything and start new. I added pictures of journey. The tablet is a ONN ONA19TBD03. I’m sorry I couldn’t find that option to chose.