Since XSplit is unavailable, you need software built specifically for macOS. Here are the top three replacements, ranging from free to professional.
If you go to the official XSplit website and click "Download," you will receive an .exe file (Windows Executable). MacOS cannot run this file natively. xsplit mac download
Currently, XSplit has for a native macOS version of its Broadcaster software. To use it on a Mac, you must run it through a Windows environment: Since XSplit is unavailable, you need software built