Add auth token to manual Next.js setup snippet (#7254)

Co-authored-by: Shana Matthews <[email protected]>

Author: Luca Forstner

src/platforms/javascript/guides/nextjs/manual-setup.mdx

@@ -135,12 +135,16 @@ const sentryWebpackPluginOptions = {
   // Additional config options for the Sentry Webpack plugin. Keep in mind that
   // the following options are set automatically, and overriding them is not
   // recommended:
-  //   release, url, authToken, configFile, stripPrefix,
-  //   urlPrefix, include, ignore
+  //   release, url, configFile, stripPrefix, urlPrefix, include, ignore
 
   org: "___ORG_SLUG___",
   project: "___PROJECT_SLUG___",
 
+  // An auth token is required for uploading source maps.
+  // You can get an auth token from https://sentry.io/settings/account/api/auth-tokens/
+  // The token must have `project:releases` and `org:read` scopes for uploading source maps
+  authToken: process.env.SENTRY_AUTH_TOKEN,
+
   silent: true, // Suppresses all logs
 
   // For all available options, see: