Does Plesk work with GoDaddy's reseller API to purchase domains or other operations?
GoDaddy API is not supported by Plesk
Purchasing domains from GoDaddy can be done directly from their site or implemented in a web application, which, in turn, can be hosted in Plesk.
To extend Plesk functionality, suggest this feature on our UserVoice page. Top-ranked suggestions are likely to be implemented in future releases.