You can get it as below
Download the EDK ZIP archive to your local system using one of the following
Using the Enterprise Manager Cloud Control console
a. Log in to Enterprise Manager Cloud Control.
b. From the Setup menu, select Extensibility, then select Development Kit.
The Extensibility Development Kit (EDK) page appears.
c. Under Installing the EDK, select Download the Extensibility
Development Kit to your workstation.
d. Save 18.104.22.168.0_edk_partner.zip to your local system
Please refer the doc :