Data Tag sends requests to the server Google Tag Manager. 

Event Type: 

• Standard - select from the list of predefined event names. 
• Custom - use a custom event name or select variable.

GTM server-side URL - add your tagging server URL. Use either constant or variable.

Send all data from Data Layer - if enabled, Data Tag will parse the data layer in the web GTM container and send it to the server GTM container event data. 

Send common data - adds to request page_location, page_path, page_hostname, page_referrer, page_title, page_encoding, screen_resolution, viewport_size.

Event Data - use event data to send event information to the server GTM. You can select to transform event data to lowercase, trim, hash using Base64, SHA256 (Base64 Encoded), SHA256 (HEX Encoded), MD5. You can store event data in cookies, local storage, or everywhere. Use data variable to get stored data. It helps to enrich event data when variables can’t be retrieved from the data layer or any other parameter. 

User Data - use to send user data to the server GTM. You can select to transform event data to lowercase, trim, hash using Base64, SHA256 (Base64 Encoded), SHA256 (HEX Encoded), MD5. You can store event data in cookies, local storage, or everywhere. Use data variable to get stored data. It helps to enrich event data when variables can’t be retrieved from the data layer or any other parameter. 

Settings:

• Request type - POST, GET, or Automatic.
• Path Type - /data path is set by default. You can use any path you want. Data tag uses this path to send requests to the server GTM.
• Protocol Version - protocol number used for sending a request to Data client in the server GTM.
• Add GA4 specific parameters - use this checkbox to set up server-side Google Analytics 4 based on Data Tag requests. If enabled, Data Tag will add additional parameters in GA4 format.
• Measurement ID - add your Google Analytics 4 measurement ID.

Use cases:

1. Sending Data From the web GTM to the Server GTM.
2. Avoid Google Tag Manager blocking by Adblockers.
3. How to create a data layer for server-side Google Tag Manager