i try to login using metamask, but there is something error appear, no connection, what am missing here?
I told you...

We'll need Metamask for login to the platform,
but don't forget to check the instruction (how to do it) - this one! (Read it! - Trust Me!)

You'll need to create custom RPC on your Metamask...
Read the instructions!!!
The way is looks so long down, it does cause a little laziness, but the instructions are made very easy to understand. And also that picture are really help and motivates.