Problem sharing the AccessToken between Node and Vue

i’m totally new to Okta and the workflow is quite nice.
At the moment I’m building a CRUD Rest App with Vue and NodeJS.
The login system with Okta works perfectly, but when i try to secure the API with the Access Token, the Problem starts.

I’ve integrated the AcessKey functions and routes following this Tutorial:

The problem occurs when the Vue App tries to connect to the API, Node gives me an 500 internal server Error.

Here the code of my router.js in Node.

Here my Axios client:

I hope you can help me, thank you!