Incorrect user authorization

You appear to have create a client credentials token, which generally is fine for calling public data endpoints.

To call the editors endpoint you need permission from the broadcaster, which is acheived by generating a User token with the relevant scope attached.

As you need a token that represents a user, a client credentials represents no one (well technically you clientID which isn’t a user)

As per

Authentication
OAuth user token required
Required scope: channel:read:editors

As for games, well you’ll need to be part of an organistation that owns a game!

Gets a URL that game developers can use to download analytics reports (CSV files) for their games.

Authentication
OAuth token required
Required scope: analytics:read:games

A user token is

See also