Send a revised musescore file to a user

I see that I can send notes to musescore users, but I can't send the important thing -- musical notes ! I made some minor edits to https://musescore.com/madams48508/ivory-places-henry-barraclough and then thought I would send them to madams48508 - but the contact form doesn't allow attachments.
The contact form also does not seem to indicate that the message is about a particular score.
When he gets it, he will probably want to compare it to his version, and either accept or reject the changes. If there was a score comparison thing, that would help.
Github does this kind of thing with a "pull request" where upload your changes, and then tell the owner of the project that they might want to have a look at them. The owner can accept your changes, or ignore you, depending on how he feels on the day. (And whether your changes are worthwhile or not.)(