Step 3: Click on the TMS User menu item.
Step 4: Click on the Manager sub-menu item.
Step 5: Click on “Create Extension”.
Step 6: Select an extension type.
Step 7: Give the extension a number - This should follow the previously created number.
Step 8: Click” Add Extension” to save the extension.
Note: A notification will open to inform you that the extension will be added to your next billing run.