Adobe sends me verification codes, but they don't work

I'm befuddled. You said " however when it propmpts me to place in the last dgits of my telephone number".

What happens when you attempt to enter the last digit of your telephone number?

So you do get a check code and what happens when you enter it?

None of the codes they are sending is functional. I womnder if this is a game by Adobe!

Hi, 

Adobe will sometimes ask for your multi-factor authentication code before your password, as an additional security measure. Once you’ve proved your identity with a multi-factor code or approval, we’ll ask for your password to finish logging you in.”

You have to enter your 6 digit passcode before entering your password. 

Please go through the below link and follow the steps. 

https://helpx.adobe.com/x-productkb/global/2-step-verification-account-security.html

I'm confused. You said " but when it propmpts me to put in the final dgits of my phone number".

What happens when you try to input the last digit of your phone number?

So you do get a verification code and what happens when you enter it?