Update, I also followed the directions on this module, video_embed_field_migrate → with similar results:
$ composer require drupal/video_embed_field_migrate
Using version 1.0.x-dev for drupal/video_embed_field_migrate
$ drush cache-clear drush
'drush' cache was cleared. [success]
$ drush vef_migrate field_video_media
The drush command 'vef_migrate field_video_media' could not be found.[error]
Run `drush cache-clear drush` to clear the commandfile cache if you
have installed new extensions.
arne.olafson → created an issue.
The first one ran perfectly, with thousands of rows affected, but the second one gave me an error:
Duplicate entry '1' for key 'PRIMARY'
It turned out that it was because I had uploaded a logo and favicon file. Manually deleting the records on the d9.file_managed table made it run just fine and I now have images migrated to my d9 fields. Thank you!!
arne.olafson → created an issue.
This request seems like a desirable accessibility feature, i.e. to make content accessible without having to describe to someone how to access it.