codes like 'CH' mean China, ......and 'LL' the U.S

To find where your iPhone 15 Pro Max was made, check the Model Number in Settings > General > About (tap the number to reveal the short version) and look up the leading letters on an Apple support page or iPhone Wiki for the specific country code, as codes like 'CH' mean China, 'ZP' Hong Kong/Macau, and 'LL' the U.S