That's what a "watching" wallet does: it watches the address but doesn't allow you to make any transactions. If you want to transact, create a regular wallet, not a watch-only. The rest of the process would be same, import private key etc.
Hmmm, I don't know what I'am doing wrong with it .
I think it's not possible with this one
https://github.com/BTCP-community/electrum-zcl/releases/tag/Z!1.0.0