Adding a trusted phone number to a Corporate Apple Developer Account?

My company has an Apple Developer Account (which has the Account Holder role) to which I have access.

I have possession of an iPad which is signed in with the the Apple ID which is the Account Holder. I use this account and this device for 2FA.

Others in my company have access to the ID, but they cannot sign-in to App Store Connect to, say, accept any changes in T&C.

How do I give another ID and another device this capability? What if I am out of the country and don’t have the iPad with me. I see that I can add another trusted phone number, but that requires a device that isn’t already associated with 2FA. Does that mean we have an iPhone with a mobile phone number?

I am looking for best practices for Account Holder corporate management.

Any assistance would be greatly appreciated.