Ah, ok. 

The m3u8, if you have it, *may* be all that you need. It’s a text file playlist - based off of the original m3u playlist format. This is called a “manifest”. 

It contains a list of files for the player to play, in order of playout. The files could be audio, video or both (muxed). 

Sometimes, the manifest will actually be a playlist that links to other playlists instead of media files, often called a “master manifest”. This will be obvious, because it will reference different video resolutions and codecs. You likely want the highest quality, if so. These files exist to allow a player to jump between qualities (called variants/layers/renditions) if bandwidth changes. 

A “container” is a file that holds the encoded content and metadata about that encoded content (codec, duration, audio/video timing, captions, etc). It’s the “TS” or “MP4” part of a video. Think of it as a sort of zip file (tho the compression happens on the encoding within the container). 

So to download, grab the m3u8 manifest. If it’s a master, grab the highest quality m3u8 referenced within it. Then grab all of the ts files within the appropriate manifest. Now you just have to combine them.  That, unfortunately, may be a bit complicated to go over in this post. FFMPEG can do it, I think. But I am not sure of all of the flags needed. 

Now you said this was a live stream? Or is it a recording of a live stream? This matters because a live stream often only has a snapshot of the latest TS files. Ie, it gets rid of old ones and adds the new ones. If it’s a recording, it will contain it all. 

Clear as mud? 

 https://data.zap.stream/recording/ae7c11f0-0207-4b5f-990c-4c75bf3cf9f8.m3u8

This is what I am working with  

 Ok. Have you tried a capture from VLC? 

 im trying m3u8 converter extension, should i use VLC instead? 

 Never used the extension. No idea how good it is, if at all. VLC can do a decent job. Video varies wildly, so there’s a ton of variables the influences chances of success with these tools unless they get deep into it (like the method I described, which is much more advanced). 

 Finally got a chance to look at it. 

Not a master manifest - just a plain one. You could grab all of the TS files referenced in it. 

Standard VOD, so no concern about a live window. No encryption, either. 

Worst-case, you could drop all of these files (in order) into any movie editor to stitch them together. 

There are other tools out there, but can’t vouch for them. VLC could do this in multiple ways. Here’s a CLI option: 

https://wiki.videolan.org/VLC_HowTo/Merge_videos_together/