[CodeArtifact] Repository not found

I have a private package in a CodeArtifact repository but it will not download/install. I have tried installing from a package.json and copying and pasting the suggested command from AWS dashboard; npm install @myproject/authentication@1.0.93.

I am getting an error

npm ERR! code E404
npm ERR! 404 Not Found - GET https://company-112233445566.d.codeartifact.eu-west-1.amazonaws.com/npm/myrepo/@myproject%2fauthentication - Repository not found.
npm ERR! 404
npm ERR! 404  '@myproject/authentication@1.0.93' is not in this registry.

my .npmrc includes

@myproject:registry=https://company-112233445566.d.codeartifact.eu-west-1.amazonaws.com/npm/myrepo/
//company-112233445566.d.codeartifact.eu-west-1.amazonaws.com/npm/myrepo/:always-auth=true
//company-112233445566.d.codeartifact.eu-west-1.amazonaws.com/npm/myrepo/:_authToken=${CODEARTIFACT_AUTH_TOKEN}

However,I can see the repo on the dsahboard and the query aws codeartifact list-package-versions --package authentication --domain company --domain-owner 112233445566 --repository myrepo --format npm --namespace myproject returns

{
    "versions": [
        {
            "version": "1.0.93",
            "revision": "<somebase64string>",
            "status": "Published",
            "origin": {
                "domainEntryPoint": {
                    "repositoryName": "myrepo"
                },
                "originType": "INTERNAL"
            }
        }
    ],
    "defaultDisplayVersion": "1.0.93",
    "format": "npm",
    "package": "authentication",
    "namespace": "myproject"
}

Could it be the %2f being used in the request rather then a '/'?

I should mention that I am using WSL (Ubuntu) on Windows10. I do not think this is the issue however, since this setup work with a private verdaccio server (https://verdaccio.org/).