If you have elixir in your path, you should just be able to install the extension in vscode and it should just work.

Other data that might help debug,

1. is there any messages in the output tab of the builtin terminal?
2. is there there anything is the .elixir_ls in your project directory (same level as your project mix.exs)

I’m having the same issue. Actually Intellisense works for elixir methods, but not for my own classes. Is it suppose to work this way?

There are neither methods, nor classes in elixir, so I assume you are meaning functions and modules.

Can you tell us how you manage your erlang/elixir installation and how you start vs code?

If you use anything other than your systems installation of elixir and starting vs code from the GUI, you are doing it wrong.

Try starting it from the terminal you used to verify that the correct version of erlang and elixir are available.