Why Approvals are not receiving when prospective and spend authorised creation in External process?

Hi,

• I am creating prospective and spend authorised supplier through External process.
• I created a approvals like Supplier administrator will approve the Prospective and supplier manager will approve the spend authorised.
• I have a Supplier manager role and Supplier Administrator roles.
• Even though i having a Those two roles, i didn't receive any notification to approve the suppliers.

• I was checked in BPM work list. No result

• What Might be the reason for not receiving the notifications.