With the auto-reply, you can only use a static response text, i.e. no
personalized/dynamic content is possible here. For a dynamic reply, you
may process incoming SMS messages using a workflow (see docu link below)
though this won't be in real-time then
https://experienceleague.adobe.com/docs/campaign-standard/using/communication-channels/sms-messages/managing-incoming-sms.html?lang=en