Blocking URLs and Websites on Managed macOS Devices with Intune (Help Needed!)

1. Most effective way:
   The most effective way to achieve your goals using Intune would be to leverage the features of Microsoft Defender’s Network Protection and Web Content Filtering. These features can help you block specific URLs and websites.

2. Specific settings or configuration profiles:
   For blocking specific URLs, you can use the “Web Content Filtering” feature in Microsoft Defender. For blocking specific websites, you can use the “Custom Indicators of Compromise” feature in Microsoft Defender.

3. Consistency across macOS versions:
   To ensure that your blocking rules are applied consistently across all macOS versions, you can use the device compliance settings in Intune. These settings allow you to set a minimum or maximum OS version, set password rules, and more.

4. Implementing whitelisting:
   You can use the Tenant Allow/Block List feature in Microsoft 365. This feature allows admins to create and manage entries for URLs. You can create allow entries for URLs that you want to whitelist.

5. Best practices:
   Start with a small set of devices to test your configurations. Evaluate the impact of your policies and verify there are no issues or broken workflows. Gradually deploy your configurations to a larger set of devices until completely rolled out.

For additional information you can take a look at these references:
Use network protection to help prevent macOS connections to bad sites | Microsoft Learn
Web content filtering | Microsoft Learn
macOS device compliance settings in Microsoft Intune | Microsoft Learn
Allow or block URLs using the Tenant Allow/Block List | Microsoft Learn
macOS device settings in Microsoft Intune | Microsoft Learn