I want to add crypto certificate in IBM Datapower using API Call. How can I implement this Kindly help me. I already read all the documentation about REST Management Interface and XML Management Interface I did not found any good information.
You need to do this in two separate steps, upload the file/s and then create the IDCRED/CERT objects.
Using SOMA (XML Management) you'd use dp:set-file and with the REST management you'd need to base64 encode the file and use the endpoint /mgmt/filestore/{domain}/{directory}/{filename}.
After the file/s is/are uploaded you can go ahead and create the CERT object/s point to the files.
Have a look at the awesome Config-Manager which can help you with a number of tasks; https://github.com/ibm-datapower/datapower-configuration-manager