Scope
How to export cancellation reason codes?
I am not able to view or download the cancellation reasons
Summary
You can see export the reason codes from the Subscription Index Page > Filter list > Reason codes. Then click Export > Export as CSV.
Solution
If you would like to export subscription data to see the various cancellation reason, you need to perform an export of the subscriptions you want. From there you can look at the canceled reason. You can do this by going into the subscriptions tab, applying the desired filter, and then exporting the subscriptions. Navigate from Subscription Index Page > Filter list > Reason codes.
If you would like to export subscription data to see the various cancellation reason, you need to perform an export of the subscriptions you want. From there you can look at the canceled reason. You can do this by going into the subscriptions tab, applying the desired filter, and then exporting the subscriptions. Navigate from Subscription Index Page > Filter list > Reason codes.

Note: On the recent UI enhancement you can now scroll the index pages - Customers, Subscriptions, Invoices, and Credit Notes vertically. Earlier, the pages will be paginated which may prolong your search however with the new enhancement as you scroll down the list it will load all other data in a single page as highlighted below on the screenshot. Refer to this link for more information.
Then click Export > Export as CSV.
Once exported, you can view the list of reason codes.

If you are using API, then please refer to this link to know more about export subscriptions with reason codes.