@Martin B Thanks for reaching out. You can try any of the below to resolve the issue
- You can try creating the function app first. Once its created, refresh your resources from vscode. When you select "Deploy..." from your workspace, it should prompt you to select the function app you created.
- Make sure you install all the latest Prerequisites as documented here. In VSCode use the shortcut Ctrl + Shift + P to bring up VS Code command palette and first signout Azure: Sign Out and then sign in using the command 'Azure: Sign In' in the command palette. Just search for 'Azure: Sign In' or 'Azure: Sign Out' in the command palette and sign in/sign out to the account. Similarly, if you multiple tenant/subscription make sure to select the right tenant/subscription using the VS Code command palette.
- Make sure you have the right permission to view/deploy the function app on the selected tenant/subscription.
In case if you still face the issue then please share the screenshot of your VS code along with the version of the extension, function runtime.