I recorded a screen recording for 2 hours, after which a preview window came out, I clicked on it and there was a button to share the recording, I selected telegram, then the preview was minimized and the recording was not on the computer and telegra

The Telegram video size limit is 2 GB, which is quite high imho, but a 2 hour screen recording can exceed that.

When doing a screen recording, first save the media file, then verify it. I would advise to not do anything before saving. After that, you may choose to convert to smaller size and/or share.

When doing a screen recording, you can set a save location, or have a temp file “in memory” in QuickTime Player. Prefer to save to the Desktop (initially; you can move it later). Avoid external drives or in QuickTime Player, as it can go wrong with video loss as result.

When selecting a share option, please wait while the system does the necessary steps in the background. 2 GB is a lot to process, it may take a significant amount of time.

along with Urquhart1244's good advice, I will add this question. do you have "Show Floating Thumbnail" enabled? when active, the recording will temporarily show up on the bottom right of your screen before being saved and moving to the chosen “save to” location. I have seen issues when others (and myself) that when interacting with the "floating thumbnail" it can cause the recording to disappear, never to be found again. that is why I personally ALWAYS leave "show floating thumbnail" disabled.