Forwarding calls from your AT&T mobile number to your 2nd Phone Number number is indeed possible, provided the 2nd Phone Number number is a US number. Here's how you can do it:
Check with AT&T:
Since methods for call forwarding may vary slightly among providers, it's advisable to reach out to AT&T customer support directly. They can furnish you with specific instructions tailored to your current plan and device. Typically, call forwarding entails dialing a particular code sequence followed by the destination number (your 2nd Phone Number number in this case).
Verify your 2nd Phone Number number:
Ensure that your 2nd Phone Number number is activated and ready to receive calls. You can verify this within the 2nd Phone Number app itself.
Additional Tips:
Call forwarding may result in additional charges from AT&T depending on your plan. Refer to their website or contact them for further details.
If you frequently require call forwarding, explore alternative solutions within the 2nd Phone Number app, such as setting up call forwarding directly through the app's features.