By default, @Sign synchronizes your document status every 15 minutes. However, for a truly “live” experience, you can enable Webhooks. This configuration allows Zoho Sign to push updates to Salesforce the exact second a document is viewed or signed, triggering immediate follow-up actions and providing your team with up-to-the-minute data.
To begin, enable Salesforce Sites in your environment by following the Salesforce setup guidelines: Salesforce Sites Setup Guide.
Once the site is created, ensure it is activated. After activation, you can proceed with configuring access for the webhook.
Salesforce Setup
Go to Setup and select Sites. Note down the Site URL.

Select the Site Label, then click on Public Access Settings.

Locate Enabled Apex Class Access, then click Edit.

Add adser.AdSignWebhookController to the Enabled Apex Classes list, then click Save.

Licenses
If your organization has an @Sign license, you do not need to assign individual licenses. However, when using user-based licenses, you must assign a license to the Site Guest User, as required by the Salesforce platform.
Zoho Sign Setup
Refer to the Zoho article for instructions on adding a webhook: Zoho Sign Webhooks Management.
Use the following as the webhook Callback URL:
[Site URL]/services/apexrest/adser/adsign/webhook