Day 4 - Authentication Error

Hello there

I’m enjoying the 15 day challenge - on Day 4 and hit a problem. I’ve come to the submit stage and I get this error;

{
    "error": {
        "name": "AuthenticationError",
        "message": "Invalid API Key. Every request requires a valid API Key to be sent."
    }
}

I am able to send my solutions to Day 3, Day 2 etc without any issues. I’ve not done anything different here, I got the collection ID, put it into the submit collection request for Day 4 and I get this error.

Its stopping me from progressing, so any ideas I’d be grateful!

EDIT; the console also says

TypeError: Cannot read properties of undefined (reading 'item')

Thanks

I found it, it was missing the x-api-key from the submit request.