Found a solution by going to "Transform Data" and changing the "Source" code to dynamically get the last value in reviews.

= Python.Execute("#(lf)def extract_findings(filename):#(lf)    
...

#(lf)filename = "&"""" &Record.Field(Table.FirstN(Table.Sort(reviews, 
{{"createdon", Order.Descending}}), 1){0}, "attachment")& """"&"#(lf)
findings_df = extract_findings(filename)#(lf)
findings_df"
)