I think you have have accidentally clicked through at some point. There is no going back.
Now that I review your earlier posts, I think I was giving you the wrong advice the whole time. Those dialogs that you have clearly instruct you to "finish" setting up two-factor authentication.
I would like to think that I was just spouting off above when I said "there is no going back". But apparently, I was correct. Here are instructions from Apple about two-factor authentication: Two-factor authentication for Apple ID - Apple Support
Jump down to the end, under "Can I turn off two-factor authentication after I’ve turned it on?". It says:
You can't turn off two-factor authentication for some accounts created in iOS 10.3 or macOS Sierra 10.12.4 and later. If you created your Apple ID in an earlier version of iOS or macOS, you can turn off two-factor authentication.
So, the question is, when did you create your Apple ID?