Add documentation and example for brand_id usage

Co-authored-by: mehmet-yoti <[email protected]>

Author: Copilot

examples/doc_scan/README.md

@@ -6,3 +6,27 @@
 1. Install the dependencies with `pip install -r requirements.txt`
 1. Start the server `flask run --cert=adhoc`
 1. Visit `https://localhost:5000`
+
+## Customizing the IDV Session with Brand ID
+
+The SDK now supports applying custom brand themes to the ID Verification iframe using the `brand_id` property. This allows businesses to maintain their brand identity throughout the verification process.
+
+### Usage
+
+When creating a session, you can specify a `brand_id` in the SDK configuration:
+
+```python
+from yoti_python_sdk.doc_scan import SdkConfigBuilder
+
+sdk_config = (
+    SdkConfigBuilder()
+    .with_allows_camera_and_upload()
+    .with_primary_colour("#2d9fff")
+    .with_brand_id("your-brand-id-here")  # Add your brand ID here
+    .with_success_url("https://yoursite.com/success")
+    .with_error_url("https://yoursite.com/error")
+    .build()
+)
+```
+
+The `brand_id` is optional. If not provided, the default Yoti branding will be used. Contact Yoti support to obtain a brand ID for your organization.

examples/doc_scan/app.py

@@ -47,6 +47,8 @@ def create_session():
         .with_preset_issuing_country("GBR")
         .with_success_url("{url}/success".format(url=YOTI_APP_BASE_URL))
         .with_error_url("{url}/error".format(url=YOTI_APP_BASE_URL))
+        # Uncomment the line below to apply a custom brand theme
+        # .with_brand_id("your-brand-id-here")
         .build()
     )