This eMMC module does not have pre-installed OS. It is suitable for ODROID-H2/H3/H3+, but also XU4 , N2+, M1 and C4. To install OS on the eMMC module see OS Installation Guide. You will need the USB3.0 eMMC Module Writer 2 (see below).
For ODROID-H2/H3/H3+, after attaching the eMMC module to the H2/H3/H3+, connect the USB stick with the OS installation image to the H2/H3/H3+ and install the OS in the eMMC.
More information is available on the website of Hardkernel.