New iPad can’t start “WeChat”!

I just bought a iPat Air. The ID: zpxykm@gmail.com and Password: “A..le3…”(9-digit)

I tried to install “WeChat” The steps are: (1) On the home screen of iPad, click the icon “App Store”

(2)In the “App Store” find the “WeChat for iPad” then download and install it.

When the installation came a sub-step telling me to input my account name and password.

I inputted my Apple ID and password, it says: “This user does not exist” !!!

Now the nice icon of WeChat--green ground with 2-white-boy- is already on my iPad home screen, but

it always stop at “log in with account name and password”!!

My Apple ID and Password can log into Apple store freely, why can not to be used in the “App Store” for the

“WeChat” Help me please!