The preapproveinvoice RPC command submits the bolt11 invoice to
the HSM to check that it is approved for payment.
Generally the preapproveinvoice request does not need to be made
explicitly, it is automatically generated as part of a pay request.
By default, the HSM will approve all preapproveinvoice requests.
If a remote signer is being used it might decline an preapproveinvoice
request because it would exceed velocity controls, is not covered by
allowlist controls, was declined manually, or other reasons.
If a remote signer declines a preapproveinvoice request a subsequent
attempt to pay the invoice anyway will fail; the signer will refuse to sign
On success, an empty object is returned.
Ken Sedgwick <[email protected]> is mainly responsible.
Main web site: https://github.com/ElementsProject/lightning