You can't connect your Trezor directly to Bitcoin Core.
Your information is outdated. It is (and has been since 22.0) possible to have Bitcoin Core connect directly to various hardware wallets.
Again, you don't need the onion address of your full node, but of your Electrum server. To do this you need to run an Electrum server and as far as I understand, you don't. Check spesmilo's
"How To". If that seems difficult and you're using RPi, pick a full node OS, such as
Umbrel or
Raspibolt.
If you don't have a RPi neither you think you're confident in your technical skills, consider buying one. It's
cheap and you don't have to mess with things you don't understand well.
It sounds like they want to run their own Electrum server, not connect Electrum to a server.
Two things i need help with from bitcoin experts please:
1. just installed the bitcoin core v.22 full node on mac Big Sur, but can't connect my Trezor with the UI.
can some experts please advise how to install the HWI, currently when I create a new wallet the option for "external signer" is grayed out, not an option for me to use my trezor with
Download the HWI Mac binary from
https://github.com/bitcoin-core/HWI/releases and extract it to some place. Remember the full path to the
hwi binary that you extracted.
In your bitcoin.conf, add
signer=<path> where
<path> is the path to the HWI binary.
When you start Bitcoin Core now, you should be able to create a walle with external signer.
2. how can i find my full node .onion address so i can use an electrum server with my own node remotely?
You can use the
getnetworkinfo RPC. If you have enabled hidden service creation,
getnetworkinfo will have your onion address listed in
localaddresses.