Submit a draw request for a loan application. This endpoint handles both regular draw requests
and final draw requests with completion certificate upload (files and/or JSON metadata).

The system automatically determines if this is a final draw based on the loan's disbursement state.
For final draws, completion certificate documentation is required.

Gated funding loans

For loans configured with gated funding (disbursement check type Gated - Thrive Approval
or Gated - Borrower Approval), draw requests create a funding request instead of
immediately creating a merchant disbursement. Calculated draw amounts are returned in the
response, but funding is processed only after the request is approved.

• merchantDisbursementId is null — no disbursement record is created until the funding
  request is approved and the draw is executed.
• gatedFundingRequestUid — identifier for the pending funding request.
• gatedFundingStatus — current review state (INTERNAL_REVIEW when Thrive admin approval
  is required, BORROWER_REVIEW when borrower approval is required).
• gatedFundingMessage — human-readable status message for the funding request.

Use gatedFundingRequestUid (not merchantDisbursementId) to track pending draws on gated
loans. Submitting another draw while a funding request is under review returns HTTP 400.

For additional information, see the Draw Requests Guide in the Guides section.