Open the loan sheet from a country card in the World tab and propose an amount, a rate and a term. They weigh your debt load, your record and your relations; if they accept, the money really moves from their treasury to yours.
Interest and principal flow from your budget to the lender every day. Whatever you can't cover is logged as arrears and a banner warns you at the top — no silent surprise, you see how many days you have left.
After 180 days of arrears the loan defaults and the decision is the lender's: forgive it, stretch the term, or seize your facilities and vault. Your record suffers and you can't borrow again for a while.
Some countries lend below the market on purpose, planning to take over your production. The offer card shows you the market rate too; if you can't pay, your facilities pass to the lender — judge the offer by what you can repay, not by how cheap it looks.