Plesk API: Expiration Date
There should be an option to read and modify the value of the "Expiration Date" variable on the Plesk subscriptions in the API. That would help a lot.
Plesk Tech Support shared this idea
Thank you for your feature request. We will consider the possibility of its implementation if it becomes sufficiently popular and in demand.
With current version, to get all subscriptions that will expire soon must request all subscriptions, include the limits dataset, and then perform a filter.
Leaving the possibility to filter by expiration date will be a greate improvement.