The text in blocks has been renamed to rich_text, to be consistent with the database property type..

[KoditkarVedant]

To be consistent with the database property type, we have renamed the text property to rich_text. This affects the following block types: paragraph, heading_1, heading_2, heading_3, callout, quote, bulleted_list_item, numbered_list_item, to_do ,toggle, code ,template.

Here is an example of the previous text property:

{
  "type": "paragraph",
  //...other keys excluded
  "paragraph": {
    "text": [{
      "type": "text",
      "text": {
        "content": "Lacinato kale",
        "link": null
      }
    }]
  }
}

Here is an example of the updated rich_text property:

{
  "type": "paragraph",
  //...other keys excluded
  "paragraph": {
    "rich_text": [{
      "type": "text",
      "text": {
        "content": "Lacinato kale",
        "link": null
      }
    }]
  }
}

Notion changelog: https://developers.notion.com/changelog/releasing-notion-version-2022-02-22