Creating a YouTube link

Hi @종규312231671cb5 ,

"When I made a YouTube link with the <Edit | Link | Add or Edit a link> button,
Inside the Acrobat app, the video runs."

For clarity, did you mean to say that the video runs externally in the deafult web browser?

Or are you saying that a YouTube video is actually downloaded to your computer when the user clicks on that URL link, and somehow, you managed to embedded it  in the PDF document that is currently being viewed in Adobe Acrobat Pro ?

In any case, this is not really a question about Adobe Acrobat.

And It is worth noting that what you are trying to do is not accomplished with Adobe Acrobat at all (or with any other software for that matter).

As you yourself have observed, URL links are executed and handled with web browsers by default, not through PDF editors such as Adobe Acrobat.

But, you may configure the operating system to associate a file type with an executing action, a file type to a program (or app), a file type to a protocol.

This is done manually at the operating system level,  by which the user can associate an app (or program) to a file type either "By Protocol" , "By Program", or "By  File Type". 

In other words, when a user clicks on a URL link, it is the operating system that associates that action with the corresponding  file type (program or  protocol).

Therefore, it is the operating that  invokes the appropriate app or program to handle the execution of a desired file type, for example; not Adobe Acrobat.

In which case, what you'll need to do is to set up the YouTube app as default web browser.

The Pros:

You'll be able to click on a URL link that is embedded in a PDF document and it will be opened and rendered within the YouTube app directly

The Cons:

The problem with this approach is that, making the YouTube app the default web browsing app, it affects all other programs that are installed in your computer.

If, for instance, you have a Microsoft Word document with non-YouTube URL links embedded, when the user clicks on them they will open in the YouTube app too.

However, If you are on Microsoft Windows, you may be able to work around this by setting the YouTube app as the default handler for certain URL protocols rather than setting such app as the default web browsing app.

If I am not mistaken, The YouTube URL protocol that is used with live streaming URL feeda is the RTMP protocol, while URLs that are used to host regular YouTube videos (for downloading and streaming) is handled by the QUIC/HTTP3 protocol.

You just need to do some extra home work and test with different settings in your OS until you achieve the desired result(s).

Check this thread.