Overview
I had the opportunity to bulk delete multiple content items using the Drupal REST API, so this is a memo of the process.
References
For a method to bulk delete content without using the REST API, please refer to the following.
Preparation
First, enable the HTTP Basic Authentication module and the JSON:API module.
Additionally, enable DELETE in REST resources.
/admin/config/services/rest


Execution Example
The following custom library is used.
https://github.com/nakamura196/drupal_tools
You can also review the processing details at the following link.
https://nakamura196.github.io/drupal_tools/
Installation
Preparing the .env File
Execution
Run as follows.
item_ids is a list of unique values corresponding to field_name (in this case, field_item_id).
Summary
Please note that there may be bugs, so exercise caution when using this.
I hope this serves as a helpful reference.