I'm trying to find a way to change the default seller company in an invoice in Bitrix. I can see the button to trigger the change in my Bitrix UI, so as the field 'Default Company' that changes after the trigger. However, I can't find any API method which may lead me to update it. Any ideas?

I was trying to find the mentioned field containing the info about the selected default company, but found none. I also tried to find any method that may lead me to settings of 'My company' part of companies entity in Bitrix, also no luck.