I think you're asking if you can send a post request from information in a Google Sheet. This is possible, but not in the app itself. Instead, you need to access the information in another language (such as Python, explained below), and update the post request there.

1. Access Google Sheets / Create a project and an API key which accesses your sheet

   1. https://developers.google.com/workspace/guides/configure-oauth-consent

   2. https://developers.google.com/workspace/sheets/api/quickstart/python

2. Read the values within the cell with an API call to the sheet

   1. https://developers.google.com/workspace/sheets/api/guides/values

3. Use your information to make a post request as you usually would

   1. Go to Postman

   2. Find a request you want to make

   3. On the very right side, click </>

   4. Navigate to (in this case) Python - Requests

   5. Copy + Paste the code there into your Python file