Yes
This is wrong
As per
As mentioned earlier, app access tokens are only for server-to-server API requests. The grant request below requires the client secret to acquire an app access token; this also should be done only as a server-to-server request, never in client code.
You are requesting the WRONG token type.
You need an oAuth loop around: OAuth Authorization Code Flow
The type of token you have obtained is a “server to server” token and doesn’t support the channel_read scope, as theres no user attached to it.