Loan from Company to its Subsidiary


I have a US company with a subsidiary in another country.
So Main Company is listed as a “Customer” for the Subsidiary where they sell products back to main company BUT
Main company also gives Loans to the Subsidiary to operate.
Both companies run on separate ERPNext systems.

What is the best way to record Loans/Loan Payments in the subsidiary books?
I was thinking about just using simple Journal entries.
Would we have to create a new “Party” to represent the Main Company both as a Customer & Lender?
If yes, there is no way to add a new “Party Type” as “Lender”.

Any detailed help or info would be appreciated.

Thanks in advance