Update README.md

README.md

@@ -5,6 +5,7 @@ Usage
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 * Install [Python 3.8+](https://www.python.org/downloads/release/python-380/) and set up the environment variables accordingly. Otherwise, you won't be able to use the `python` command.
 * [Download](https://codeload.github.com/Dominik48N/YouTube-Downloader/zip/1.0.0) the sources of this repository and place them wherever you want.
+* Enter the command `pip install pytube` into your terminal.
 * Open the command line and execute `python main.py`.
 * Now enter the YouTube URL and the download path.
 * Enjoy the result.