We want to make a call out of our system when we integrate with your screens and click the button on your screens. Could you send us your web services and documents related to this subject?
Hey @ozenemresis
Welcome to the community 
Are you referring to the API documentation? If that’s the case, it should be accessible over here https://developers.pipedrive.com/docs/api/v1
Additionally, you can also find more details regarding caller integration also based on our tutorials. 
https://developers.pipedrive.com/tutorials/custom-floating-window-ui-caller-integrations
https://developers.pipedrive.com/tutorials/building-cti-phone-solutions-pipedrive-app