File type is not right for Youtube

My file can only be MLT, how could I change it so I could upload it to youtube?

export%20to%20youtube

Watching all of the videos in this link will really help you.
https://shotcut.org/tutorials/

‘Export’ not ‘Save’.

Save = Saving your project file (*.mlt)
Export = Export to a selected video preset (see Hudson555x’s screenshot above)

If I understand the problem correctly, YouTube only accepts video files, not project files specific to an application such as Shotcut, so you have to export to a common video file format such as mp4.

i did it but It now wants to be VLC file for some reason

Your computer is setup to play these video files with VLC. That is OK and not a problem. Upload it!