Function addPreFundedSponsor

addPreFundedSponsor(
    transaction: Transaction,
    sponsorAddress: string,
    sponsorFlags: number,
): Transaction
Adds sponsor fields to a transaction for use with pre-funded sponsorships.

This function is used when a Sponsorship ledger object already exists on-ledger with sufficient balance to cover the transaction. In this case, no sponsor signature is required - only the Sponsor and SponsorFlags fields are needed.
Parameters
- transaction: Transaction
  The transaction to add sponsor fields to.
- sponsorAddress: string
  The address of the sponsor account (must match an existing Sponsorship object on the ledger).
- sponsorFlags: number
  Flags indicating what the sponsor is paying for (spfSponsorFee = 0x00000001, spfSponsorReserve = 0x00000002).
Returns Transaction
A new transaction object with Sponsor and SponsorFlags fields added.
Throws
If:
- Sponsor and Account are the same (self-sponsorship not allowed)
- SponsorFlags is missing or invalid
Example
```
import { SponsorFlags } from 'xrpl'

const sponsoredTx = addPreFundedSponsor(
  payment,
  'rSponsorAddress123...',
  SponsorFlags.spfSponsorFee
)
```
- Defined in packages/xrpl/src/Wallet/sponsorSigner.ts:284