This video explains how to disable job schedules via IICS REST API.

Reference
For further information, refer to the following documents:
Login V2 call: https://docs.informatica.com/cloud-common-services/administrator/current-version/rest-api-reference/platform-rest-api-version-2-resources/login.html

Login V3 call: https://docs.informatica.com/cloud-common-services/administrator/current-version/rest-api-reference/platform-rest-api-version-3-resources/login.html

Scheduler: https://docs.informatica.com/cloud-common-services/administrator/current-version/rest-api-reference/platform-rest-api-version-3-resources/schedules.html