I posted a topic, this one, with a video tutorial. The topic text appears... but the video does not. Did I do something wrong?

The file may have been too large. I'd try linking to a file host.

File host? But isn't this necessary just for images? It's a youtube video...

Oh, well a link should work. (Embedding def does not.)

I went to edit, just inserting the link... but that doesn't appear either.

I'm just gonna paste the URL to a YT video on the next line

https://www.youtube.com/watch?v=1U4hVbvRr_g

Seems to work here.

I paste the url but it won't let me edit. this appears above: "You can not edit this post after the grace period. Please contact an administrator for help."

The topic is being useless under these conditions: there is no point in having a tutorial topic without a tutorial...

Okay fixed it for you.

Please contact @doctorrmo (administrator) for editing beyond 24 hrs.

OK, now the link appears for me. The contact link you indicated falls on an information page, I couldn't find a way to send messages to the admin.

Thank you, anyway! :)

The profile page has an envelope button with this link: https://inkscape.org/pt-br/~doctormo/message/

As a tutorial writer, you may need editing superpowers.

Superpowers is hard 😁 Yes, I saw the envelope icon. I clicked on it and then "new message"... and it landed on an error page.

With the link you provided, it worked. I just texted him, thanks!