In order to create an extension, you have to generate GUID for it.
Windows users can use GuidGen tool from Microsoft to obtain a GUID.
There is no known tools to genarate GUID for Linux. You can use one of online generators instead.
There is few on-line generators. You can get GUID at the page of Shailesh N. Humbad Generate GUID Online. Another generator can be found at the Homepage of family Kruithof - UUID (GUID) Generator on the WEB