So it should be asked on the H5P community:
https://h5p.org/forum
As far as I know, the H5P Interactive Video does not have a 'resume' function.
Hi!
This is possible if you activate the "save content state" option in the settings of the H5P plugin. If users are logged in, many H5P content types (including Interactive Video) will then store the current state in a regular time interval that you can set as well and whenever a task is checked. There's also a pull request for optionally adding that feature for users who are not logged in, but it will probably take some time until that one is added.
This question becomes moodle related if you are not using the H5P plugin but the H5P integration into moodle core of moodle 3.8+. To the best of my knowledge, the moodle core version does not feature the "save content state" option.
Best,
Oliver
Oliver is right. Unfortunately the very useful "Save content state" is not (yet?) available in the H5P integration into Moodle core version. I mentioned this issue in this post.
Joseph