How to use VSCode insiders with my existing extensions?

I’m trying to install VSCode insiders to get the Copilot Chat plugin to work.

I found online I could do:

  home-manager.users.pablo.programs.vscode = {
    enable = true;
    package = (pkgs.vscode.override { isInsiders = true; }).overrideAttrs (oldAttrs: rec {
      src = (builtins.fetchTarball {
        url = "";
        sha256 = "sha256:01wg94iypcgykkhfbn7dlfxmza92zsnck42ivhab53qk3jdqjcbc";
      version = "latest";
      buildInputs = oldAttrs.buildInputs ++ [ pkgs.krb5 ];

However, this created a new executable called vscode-insiders and doesn’t use the extensions I installed (home-manager.users.pablo.programs.vscode.extensions = [...]).

I tried setting isInsiders = false but then it can’t find the executable in the download (error sed: can't read /nix/store/vnf3zv365v1lsllykhh5gc8y73dniwkn-vscode-latest/bin/code: No such file or directory).

I also tried setting executableName = "code"; in the overridewAttrs, but that didn’t do anything.

So now I’m not sure what to do. The docs say

It is designed to run alongside the main build, with a separate code-insiders command and a different config path, so you can leave your main VS Code instance installed/running.

but is there a way to have it as my main vscode instance? Rather than a separate one?