How can i install EFDC? IS IT for free or not?

i decided to work with EFDC in my final research project at university about a lagoon hydrodynamics her in Morocco, i need to know if is it free to get the EFDC and the CVL grid, or should i pay something to get the licence, i couldn't install it yet, there's always an error somewhere, could you please help me to get it or at least answer me so i can understant why it didn't work for me.
Thank you
Best regards

EFDC EPA version source code is free and downloadable from this website. However, EFDC_Explorer, the pre- and post-processing tools for the model, requires a license which must be purchased. Please contact us from the sidebar "Request a quote" on this page for a quote.