Creates a simulation to preview and calculate all costs associated with a transaction before executing it. The simulation returns estimated total costs, itemized fees, exchange rates (if currency conversion is involved), expected settlement time, and any compliance requirements. Simulations are typically valid for 24 hours, after which exchange rates may change and a new simulation should be created. Always create a simulation before executing a transaction to show users accurate costs and get a simulation ID required for transaction creation. For more detailed breakdowns, consider using the v2 simulation endpoint.