Account upgrade can not verify my phone number

Question

Hello, thanks for checking my request :)

I want to create a basic pay as you go subscription.

For that, the Azure portal asks me to upgrade my account.

When verifying my number, I repeatedly get the message that an error occured and I can not continue further.

The phone number is correct.

Neither the option to text nor call works.

Any idea what I'm doing wrong or what I can try?

Thank you!

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