Method: POST gettxoutproof
Returns a hex-encoded proof that "txid" was included in a block.
NOTE: By default this function only works sometimes. This is when there is an unspent output in the utxo for this transaction.
To make it always work, you need to maintain a transaction index, using the -txindex command line option or specify the block in which the transaction is included in manually (by blockhash).
txids - array
A json array of txids to filter.
block hash - string
If specified, looks for txid in the block with this hash.