I can’t sigh into my computer

So when I turn on my computer usually I put in my pin but this time it took me to a sigh in screen and it says send code when I send code it send a code to my email when I put in the code it just goes back to the same thing what do I got to do to fix this and the blacked it my email

So when I turn on my computer usually I put in my pin but this time it took me to a sigh in screen and it says send code when I send code it send a code to my email when I put in the code it just goes back to the same thing what do I got to do to fix this and the blacked it my email