How does bitcoin reward who find the block?
A miner will create a special type of transaction known as a Coinbase transaction, as the first transaction in the block. This special transaction pays the block reward (including transaction fees) to the miner (or anyone they choose). But the miner can only put one, valid coinbase transaction in a block because otherwise the block as a whole would be invalid, and all the full nodes would reject it, making the miners work wasted because the block doesn't get onto the valid blockchain and they receive nothing. So miners are forced to play by the rules.

And yes, getblocktemplate includes the coinbase transaction if coinbasetxn is included in the capabilities list