Dev-C++ is not available for macOS.
If you have an Intel Mac, download and install Microsoft Windows via Boot Camp.
If you have an Apple silicon Mac, download Parallels hypervisor and use that to install Windows 11 Arm AArch64 as a guest. You'll also need an Arm-capable compiler with this path, or UTM or other such emulation.
Run the Dev-C++ IDE and the resulting app on Windows.
If you're tied into Microsoft Windows and its associated tooling, acquiring an x86-64 system running some semi-recent version of Windows will be your best path. That might be an Intel Mac, or any of the other available hardware options.
On macOS, LLVM Clang is the typical choice compiler, and that can either be via the command line, or via Xcode, or via various other options. Of which Dev-C++ IDE is seemingly not one.
If you can write C++ using a text editor (vim, emacs, whatever) and without depending on an IDE for development, then Clang C++ works just fine from the command line.
Or learn Xcode.
Given the five days available, pretty much any cross-platform path available here is going to be somewhat of a risk—if you can't use Xcode, or the command line tools, or such.