verification headache, endless circle of failure - help!

I have a 365 account. I got a new phone and transferred my number and apps. I set up my outlook and 365 successfully on my new laptop, but on trying with my phone, I keep getting asked to confirm the authenticator, which I can't access. I can't speak to anyone and have no access to my emails or documents, because I can't sign in. Every time I try it offers me a code, which I can't confirm. How do I resolve this please, guidance welcome.