Update service-tokens.mdx (cloudflare#22797)

Author: ranbel

src/content/docs/cloudflare-one/identity/service-tokens.mdx

@@ -63,7 +63,7 @@ To authenticate using a single header:
 2. Add the header to any HTTP request. For example,
 
 	```sh
-	curl -H "Authorization: {"CF-Access-Client-Id": "<CLIENT_ID>", "CF_Access-Client-Secret": "<CLIENT_SECRET>"}" https://app.example.com
+	curl -H "Authorization: {\"cf-access-client-id\": \"<CLIENT_ID>\", \"cf-access-client-secret\": \"<CLIENT_SECRET>\"}" https://app.example.com
 	```
 
 ### Subsequent requests