I don't use a mobile phone. How do I register for zoho mail service?

I don't use a mobile phone. How do I register for zoho mail service?

Hi,

I don't use a mobile phone, by choice.  How do I register for zoho mail service?  I don't see another way to authenticate my account.  All other online services I use offer an alternate way, such as an authenticator code or other.  Please advise.

Thank you.

AB