Identify what the receiving device requires
Write down whether the destination requires a particular filename extension, container, video codec, audio format or maximum dimensions. These are separate requirements. A service asking for MP4 should not automatically be treated as accepting any file that contains H.264 video.
Apple’s export guide describes a .mov output and supported H.264 or HEVC choices. Changing a filename from .mov to .mp4 does not perform a new export or establish that the receiving application can read the resulting file. Preserve the original while deciding on a documented conversion route.
Inspect the export that is actually offered
QuickTime’s Export As menu dims resolutions larger than the source. Apple also says the exact output resolution and data rate depend on the original. A missing higher-resolution choice is therefore a different observation from all export options being unavailable.
For supported 4K or 1080p exports, the publisher describes a smaller-file HEVC choice and a greater-compatibility H.264 choice. Compare those options with the destination’s actual requirements instead of assuming that the smaller file is universally easier to play. The receiving device and programme workflow determine the useful choice.
Verify the new copy separately
Use a distinct destination and retain the source. After an authorised export, inspect the new copy in Movie Inspector and try it on the intended receiving device. Record its actual container, encoding and dimensions rather than relying only on the export preset’s name.
If no export options are available, Apple identifies protected recordings as a possible reason. Keep that state in the report rather than presenting a renamed file as a workaround. A useful support note contains the original media characteristics, selected output, destination requirements and observed result. It distinguishes container expectations, source-limited resolution and a permission-related export restriction.