1. In the Squarespace editor, navigate to the page where you want to add schema markup.

2. Click on the "Edit" button for that page.

3. Locate the content block where you want to insert the schema markup.

4. Click on the (+) symbol to add a new content block.

5. Select the "Code" block from the available options.

6. Paste the schema markup code into the code block.

7. Click "Apply" to save the changes.

8. Preview the page to ensure that the schema markup is displaying correctly.

By following these steps, you can easily add schema markup to your Squarespace website and improve its search engine visibility.