Determining the genesis transaction value or genesis_tx
The genesis block's coinbase transaction hash will be the same as the blocks merkle root because the coinbase transaction should be the only transaction in the genesis block. You should be able to find it in chainparams.cpp if the codebase is still similar to bitcoin, like so:
https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#L125

assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));