If you want your project to be recognised as a Zephyr project, you need at least the following files inside the .vscode directory:
- cmake-kits.json
- cmake-variants.json
- mcuxpresso-tools.json
- launch.json
For some operations, the extension expects one of these files to exists, and tries to change them according to the changes you make through the extension. If the file doesn't exist, it will complain. To generate those files, you can use the Import Example from Repository feature, and use the workspace application type. From the newly generated project, copy the .vscode directory to your own project.
The downside is that some fields inside these config files are personalised per machine. For example, the toolchainPath will be equal to something like X:/Users/your-name/zephyr-sdk-0.XX.X/arm-zephyr-eabi. Luckily, these fields only need to exist to a certain extend. If you use the import project feature, the extension will automatically append these fields with proper values; just state them with empty ones:
Inside cmake-kits.json
- "ZEPHYR_BASE": ""
- "ZEPHYR_SDK_INSTALL_DIR": ""
Inside mcuxpresso-tools.json
- "toolchainPath": ""
- "toolchainVersion": ""
- "sdk.path": ""
I've added an blank .vscode directory setup in the attachments. Note that the settings.json file states that the cmake source directory can be found at ${workspaceFolder}/app; feel free to change it if this is not the case for your project.