Use API to Change Plan Duration


Is it possible to use the API to change the plan duration from monthly to yearly on our Pro plans? We have 88 plans to update. I have tried to use the recommended API call in the Cloudflare documentation but it results in the following server error:

The call:

curl --request PUT
–url “THE_API_URL_HERE ( URLs now allowed in this post apparently )”
–header “Content-Type: application/json”
–header “X-Auth-Email: [email protected]
–header “X-Auth-Key: OUR_KEY_HERE”
–data ‘{“frequency”:“yearly”}’

{“success”:false,“errors”:[{“code”:1000,“message”:“Internal Server Error”}]}

Thanks in advance for any help provided. I am thinking that I probably have the data string incorrect - perhaps more or all JSON is needed?