Change my video background to plain white without green screen

I want to make videos with a plain white background. I am using a Windows PC, and Premiere Pro 2020.

I enquired with Adobe help desk, and they suggested this Automatically match colors in Premiere Pro | Adobe Premiere Pro tutorials which really isn't what I want. I want my background removed, and a new plain white background.

I have watched various tutorials, but they seem to have slightly older versions and I can't see important tabs. For example, this video is great Chroma Key Effect Without a Green Screen (Adobe Premiere CC) - YouTube until I get to 1 min 33 secs as my menu for Difference Matte doesn't have a pull down menu. Then at 1 min 38secs, I don't have a matching tolerance tab.

Can anyone please guide me?

Thanks.