"sending video and captions " to external person who can spell.

Yes, as Ann says, mp4 with current captions burned in for them to work from.

The most efficient method for you is to get back SRT that you can just import to PR. The external person must either work in SRT and avoid changing any timecodes, adding extra empty lines, etc, or in text that you can easily convert to SRT with the original timecodes.

You can export your captions as SRT but also as a CSV that you can manipulate in Excel.

I would try the SRT method first.

You might use something like this as a tutorial for the external person:

The format of this document must be kept as is. You will be changing only the captions text.

The document looks like this:

1
00:00:05,042 --> 00:00:07,042
Caption Text 1

2
00:00:12,000 --> 00:00:14,000
Caption Text 2

The numbers (1, 2, etc) are the caption number. Do not delete or change them.

The timecode must be left exactly as it is.

You can edit the caption text, and make it more than one line, but do NOT add any empty lines.

There is exactly one empty line between the caption text and the next caption number.

If you want only one line captions, then change that instruction line to:

You can edit the caption text, but keep the captions on line, and do NOT add any empty lines.

If the "edit SRT" does not work, we can explore other options.

Stan

I would export to a mp4 with captions embedded.

Put the text in text document for easy correction.

Use Dropbox, Wetransfer or whatever for sending.