Having trouble with auth0, Next.js, AppSync via OIDC

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HI! My first question. I’ve been having trouble. For the past 2 weeks, I’ve been reading every documents I can find official/unofficial, with so many examples and my competency is still too low to understand it correctly. If anyone can help me out here, that would be great!

Tech stack:
Next.js hosted on Vercel. Using @auth0/nextjs-auth0
AWS AppSync

What I’m trying to achieve:
After logging in on Next.js application via Auth0, I’m trying to call AppSync graphql query which would have user id and ideally some more scopes from auth0 included in AppSync’s ctx.identity

What I’m having trouble with:
Calling AppSync query and have user info included in ctx.identity.

What’s working so far:
Logging into Next.js application via Auth0. I can call getAccessToken() serverside to obtain accessToken, as well as getSession/useUser to get user info on server/client side.
Also successful, is to run a AppSync query using bearer accessToken displayed on Auth0’s Application>API>test.

I’ve never done OIDC with AppSync other than Cognito, and I’m not even sure if I’m understanding the whole concept right. After I’m logged into Next.js, I can obtain accessToken via getAccessToken. I use that token as a bearer token and send the same exact query to AppSync, and it return UnauthorizedException: Valid authorization header not provided.
I replace that Access Token with the token from Auth0>Application>API>test, then it works but it doesn’t have any identity. I’m probably doing everything completely wrong, but following all the examples and guides didn’t solve my problem, and I am not even sure what I am missing.

Any guidance would be greately appreciated. I was hoping to pass more than just the user-id, but if the user-id is all I can pass, that’s fine.