You can get your node's id by typing "nodeid()" in the Console. You can enable it in "View -> Show Console". Check out
this reddit post for more instructions on getting an inbound channel from lnbig. I am not sure about how you can make it work for other nodes. Ask the other node to open a channel with you using your node's id after you connect to their node from the console.
It also doesn't work to open a channel between your two test wallets, writes this error