Diplomacy is a tool of conducting Nation's foreign policy without compromising it's fundamental principle.
When debts are being used by a country for achiving its foreign policy objective, then it is known as debt trap diplomacy.
It is often associated with China's Belt and Road Initiative, and critics argue that it is used to extend influence and gain strategic advantages while saddling countries with unsustainable debt.
Check book diplomacy: When money is used by a country to achieve it foreign policy objective. Dead trap diplomacy and cheque book diplomacy have almost the same meaning.
However, not all infrastructure lending is problematic, and borrower countries should carefully evaluate the terms of loans to avoid being exploited.