In the examples, where is the scriptPubKey address comming from?

This seemingly random address appears in several places but I will use the inscribe.test.ts file as an example https://github.com/cmdruid/tapscript/blob/master/test/example/taproot/inscribe.test.ts. Notice this code:

const txdata = Tx.create({
      vin  : [{
        // Use the txid of the funding transaction used to send the sats.
        txid: 'b8ed81aca92cd85458966de90bc0ab03409a321758c09e46090988b783459a4d',
        // Specify the index value of the output that you are going to spend from.
        vout: 0,
        // Also include the value and script of that ouput.
        prevout: {
          // Feel free to change this if you sent a different amount.
          value: 100_000,
          // This is what our address looks like in script form.
          scriptPubKey: [ 'OP_1', tpubkey ]
        },
      }],
      vout : [{
        // We are leaving behind 1000 sats as a fee to the miners.
        value: 99_000,
        // This is the new script that we are locking our funds to.
        scriptPubKey: Address.toScriptPubKey('bcrt1q6zpf4gefu4ckuud3pjch563nm7x27u4ruahz3y')
      }]
    })

See scriptPubKey: Address.toScriptPubKey('bcrt1q6zpf4gefu4ckuud3pjch563nm7x27u4ruahz3y')... Why is bcrt1q6zpf4gefu4ckuud3pjch563nm7x27u4ruahz3y being used as the script that is locking the funds? Is this just an address chosen at random or is it derived from another piece of code that I'm missing?

Does it just mean that address where the UTXO is being spent chosen at random?

cmdruid / tapscript

In the examples, where is the scriptPubKey address comming from? #35