fix. (#518)

Author: xiangkaiz

docs/knowledge-base/oauth_app/salesforce.mdx

@@ -55,6 +55,7 @@ Klavis Salesforce MCP Server uses the following OAuth scopes: `api,refresh_token
    - Enable **"Require Secret for Web Server Flow"** if your app can keep the client secret confidential
    - Enable **"Require Secret for Refresh Token Flow"**
    - Enable **"Enable Authorization Code and Credentials Flow"**
+   - Disable **"Require PKCE Extension for Supported Authorization Flows"**
 
 4. Click **"Save"** to create the app