Hi,
Easy Jtag box eMMC pinout you can find in software tab:
https://gyazo.com/8208ddb0ddd7d58e652061f70e461d11
You can use eMMC adapter like this:
https://gyazo.com/adedceee96f17cd46f2d24cd937aa6d0
or external power supply for 2.8V and 1.8V
Best Regards