tx.addInput(“d18e7106e5492baf8f3929d2d573d27d89277f3825d3836aa86ea1d843b5158b”, 1);

this: d18e7106e5492baf8f3929d2d573d27d89277f3825d3836aa86ea1d843b5158b

how do we generate a transaction hash rather than use predefined hashes?