If this is your application and your Entra instance, you may check the application's manifest (in Entra, go to app registrations, click your app, then click manifest) and make sure there isn't an accessTokenAcceptedVersion or requestedAccessTokenVersion that is set to 1. That would require you to use the older endpoints, not the v2 ones you are trying to access. It will need to be set to null or 2.

No need to get fancy with extra apps and paid services. You can usually email a text message to a phone using plain old SMTP if you know the provider so you can look up the SMS gateway for them. Here are some of the biggest ones, at least where I am:

• Verizon & Xfinity: vtext.com
• AT&T: txt.att.net
• T-Mobile: tmomail.net
• Sprint: messaging.sprintpcs.com
• Boost Mobile: sms.myboostmobile.com

If your provider isn't on that list, you can most likely find the SMS gateway via a simple Google search. Then you can send an email using the phone number and that domain as the recipient, and it will go to the phone as a text message with a subject line. For example, if you send an email to a Verizon user, the email address would look something like 5551234567@vtext.com. You can even do this from within Outlook or Gmail if you want to test it out. Mind the character limits, of course.

Several of these are already stored in IRIS. When you create or edit a user, you have an option there to select a mobile provider. You can also add new providers which requires a name and the SMS gateway. These are stored in a table called %SYS.PhoneProviders.