For a lot of it: No loans have been made, no obligations sold, No foreign or domestic entity has handed over "real money" No interest rate has been set.
For other parts the US government has bought its own obligations.
And then there are parts that are actually loans from other entities.
If they wanted, they could mint a few $1 trillion USD coins and whoosh the money exists.
The US is able to do this due to the special status of the USD as a reserve currency and general trust.
Venezuela is not able to do this because they lack the might and power od USD. Nor would Norway.
Under Covid Norway spent "real money" from their piggy bank. The US spent a lot of invented money. (But also, other categories)
https://www.investopedia.com/terms/t/trillion-dollar-coin.as... https://www.investopedia.com/government-stimulus-efforts-to-...