In that frustrated moment where the code is right but doesn't work...
Boss is a non-technical guy who's like I don't care just get it done and I'm just sitting here staring at the screen not knowing what to do...

Debug it.

Divide the execution in small parts that you can test independently and do it.

Test each part even though you think they're working ok. And test with different datasets to make sure you're not missing some scenarios.