Hi Nazar 

Thanks for posting in the Lucidchart Community! Unfortunately C4 shapes are not currently supported in Lucidchart. If you like to see that shape library available in Lucidchart in the future would you mind adding your idea to our product feedback section? Ideas submitted there are passed on to the product development team for their consideration and used to inform them what shape additions would be most useful to our customers. 

As a workaround you can import a C4 custom shape library to Lucidchart. To go over the details of how to do that please check out the 'Import and Search for Shapes and Images' section of our Shape Libraries article. 

Thanks for your request – we are always looking for ways to improve Lucidchart and your feedback is the best way for us to do that!