Currently notification emails aren't sent when payslips are uploaded from Sage 50cloud Payroll. However a workaround if you subscribe to Sage HR's Core HR module, is to use announcements and create a post to inform employees when payslips are ready.
📌TIP: You can check if you have the Core HR module as an admin via Settings > Billing
Create an announcement
For steps on how to create and publish an announcement - Read more >
📎NOTE: Before you publish an announcement, select Notify employees to ensure they receive this update by email too.