1.How do I leave feedback on Etsy app with the cancelled transaction?
Because you have cancelled the order,so you cannot review on the product.
Following is the way how to leave a feedback after purchasing:
To leave feedback, follow these steps:
1、While signed in to your Etsy account, click the Your Account link along the top of any Etsy page.
2、Click the Feedback link on the left side of the screen.
3、Click the Positive, Neutral, or Negative option button under the transaction you want to rate.