If you’re running the free version on your own node you use your existing channels. With the hosted version, I haven’t seen a way to add channels from TOR nodes, I don’t think that’s possible.

If you just need inbound liquidity, go to the advanced options and you can choose your LSP. nostr:npub1l0ans4w4psmcv6hsqjz2v3mxszhputlsfn4emkynv3jlwrfez59s35q0ug currently has the lowest prices for liquidity.