When the auction is open and there is balancing group, you receive the relevant Balancing group information as a response:
NOTE: The Balancing group and Portfolio code IDs are different for different direction (ENTRY/EXIT) in the same auction. Thus, for bundled auctions, you have to ID for both sides. You need to use the same auction ID, but one for direction ENTRY and another one request with EXIT.
2. When you collected all relevant information (auction ID etc.), the bid can be placed:
You can remove the fields, which are not needed for your bid. For example, if the entry and exit TSOs require only portfolio code and balancing group, respectively, the Json tree should be as below:
When the Balancing group/Portfolio code is missing or wrong, the following error message appears:
In this article, you can find instructions to see the exact reason behind the error.
And when you open the browser source page (F12 button) and go to the Network section, you can see the information about missing or wrong Balancing Group: