The heist fails not because of Vi’s leadership but because Powder’s inherent instability (later revealed as magical sensitivity) triggers catastrophe. This is the inciting incident for the entire series.
If you cannot find a script, find the subtitles. OpenSubtitles.org and Subscene host .srt files for Arcane Episode 1.
This is the most common destination for "scripts." While technically a transcript of the dialogue and sound cues rather than a professional screenplay format, it provides every word spoken in Episode 1.