Function initializePaymentSheet

initializePaymentSheet(configuration: PaymentSheetConfiguration): Promise<void>
Validates and stores configuration for the next native payment-sheet presentation.

Initialization is deliberately separate from presentation so an application can prepare Checkout before opening a modal. It validates client-owned options only; the SDK does not retrieve the Order or begin payment until presentPaymentSheet is called.

Call this again when the Order ID or presentation options change. Do not include an Inttegro API key: mobile applications use the public Checkout Order ID created and finalized by the merchant backend.
Parameters
- configuration: PaymentSheetConfiguration
  Checkout identity, return URL, appearance, telemetry, and optional presentation features.
Returns Promise<void>
Throws
An error when the native module is not linked, another sheet is active, or the configuration is malformed.
Example
```
await initializePaymentSheet({
  orderId: checkout.orderId,
  returnURL: 'merchant-app://inttegro-return',
});
```
- Defined in payment-sheet.ts:47