Delete attachments in merging tickets via API

With this endpoint, I can delete the attachments from closed tickets, however unable to delete attachments from specific merging comment.

It returns an error message "400 bad request" for the merging comment. Below is the API request I run but return error. 

curl --location --request PUT 'https://xxx.zendesk.com/api/v2/comment_redactions/xxx' \
--header 'Accept: application/json' \
--header 'Authorization: Basic [token]' \
--header 'Content-Type: application/json' \
--header 'Cookie: __cfruid=xxx; _zendesk_cookie=xxx \
--data '{"ticket_id":xxx,"external_attachment_urls":["https://xxx.zendesk.com/attachments/token/xxx/?name=xxx.jpg"]}'

Note:

• Some information is redacted for privacy.
• The redacted attachment was successfully removed from the original ticket, but not from the merged ticket.

Anyone know how to solve this and use API redact to delete attachments in merging tickets?