How to add dotnet user-secrets in a devcontainer.json file for GitHub Codespaces?

Question

I want to create a devcontainer.json file that does the following:

1. Installs .NET SDK, Nodejs, Git and Git LFS.
2. Installs some custom extensions to VS code.
3. Runs some commands on the terminal when the container is created to add user secrets to a .NET project and to create a .env.development file for a react project.

So far, I can complete 1 and 2 with no issues, however, I cannot figure out a way to do number 3. I tried using the "postCreateCommand" and even the "postStartCommand" but it doesn't work. When I open the codespace, I can see the user-secrets for the .NET project are still empty and the .env.development doesn't exist.

I cannot figure out why this is happening. I can run each command if the json file manually in the terminal and they work fine. I also thought that perhaps the commands where being run at a different directory but if the starting directory is /workspace/<repo_name> then I don't see that as a problem. I'm also not sure if the problem is because of racing conditions (e.g., using the dotnet cli before it's available) and the logs I get from GitHub are very limited.

Is it possibleto run commands that will add user-secrets through the dotnet cli and create a text file?

This is my current devcontainer.json configuration:

{
  // Name for the dev container displayed in the UI
  "name": "MyBlog Default Dev Container",
  // Base image meant to serve as a starting point for creating development container images for various programming languages and tools
  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
  // Features to add to the dev container. More info: https://containers.dev/features.
  "features": {
    "ghcr.io/devcontainers/features/dotnet:1": {
      "version": "latest"
    },
    "ghcr.io/devcontainers/features/node:1": {
      "version": "latest"
    },
    "ghcr.io/devcontainers/features/git:1": {
      "version": "latest",
      "ppa": "false"
    },
    "ghcr.io/devcontainers/features/git-lfs:1": {
      "version": "latest"
    }
  },
  // Configure tool-specific properties.
  "customizations": {
    // Configure properties specific to VS Code.
    "vscode": {
      // Add the IDs of extensions you want installed when the container is created.
      "extensions": [
        "ms-dotnettools.csharp",
        "yzhang.markdown-all-in-one",
        "sibiraj-s.vscode-scss-formatter",
        "dbaeumer.vscode-eslint",
        "dsznajder.es7-react-js-snippets",
        "adrianwilczynski.user-secrets"
      ]
    }
  },
  // Use 'postStartCommand' to run commands after the container is started.
  "postStartCommand": [
    "export ASPNETCORE_ENVIRONMENT=Development",
    "dotnet user-secrets set ConnectionStrings:MYBLOG_SQLITE ${CONNSTR_MYBLOG_SQLITE_LOCAL} --project ./src/MyBlog.WebApi/MyBlog.WebApi.csproj",
    "dotnet user-secrets set AzureAd:Instance https://login.microsoftonline.com/ --project ./src/MyBlog.WebApi/MyBlog.WebApi.csproj",
    "dotnet user-secrets set AzureAd:ClientId ${AZURE_AD_CLIENT_ID} --project ./src/MyBlog.WebApi/MyBlog.WebApi.csproj",
    "dotnet user-secrets set AzureAd:TenantId ${AZURE_AD_TENANT_ID} --project ./src/MyBlog.WebApi/MyBlog.WebApi.csproj",
    "echo REACT_APP_SERVER_URL=http://localhost:5000 > ./src/react-myblog/.env.development",
    "echo REACT_APP_REDIRECT_URL=http://localhost:3000 >> ./src/react-myblog/.env.development",
    "echo REACT_APP_CLIENT_ID=${AZURE_AD_CLIENT_ID} >> ./src/react-myblog/.env.development",
    "echo REACT_APP_TENANT_ID=${AZURE_AD_TENANT_ID} >> ./src/react-myblog/.env.development"
  ]
  // This ensures that the commands you run within the container execute with the correct permissions, and the file ownership and permissions align with the "codespace" user
  //"remoteUser": "codespace",
  //"containerUser": "codespace",
  // Specify a list of ports that should be forwarded from the Dev Container to the local machine
  //"forwardPorts": [3000, 5000,5001]
}