This API gets the approve/reject page URL for the given approval request. This API accepts the approval request object as input parameter. 

APISignature
getApproveRejectPageUrlwebService static String getApproveRejectPageUrl(Apttus_Approval__Approval_Request__c requestSO)
Request Parameters
NameTypeRequired?Description

Approval_Request__c requestSO

ObjectYesThe approval request object.
Response Parameter
NameTypeDescription
approveRejectPageURLStringThe URL of the approve/reject page.