I know its been awhile for this question. I had the same issue.
1. Validate that outbound http is allowed from your splunk server
curl -k -X GET -H 'accept:application/json' -H 'content-type:application/json' --compressed -H 'Accept-Encoding:gzip,deflate' -u <THIRD_PARTY_API_KEY>:<API_KEY> 'https://api.amp.cisco.com/v1/computers'
If you get a list of computers back then you are good.
etc\apps\amp4e_events_input\bin\pika\adapters and look for
DO_HANDSHAKE = True and change it to
I have gone through all the details and pre-requisites and all the properties are met.
I have all the details from API, key and Clinet ID. But the only thing is after installing the App I am not getting the Input tab.