The following HTTP Event Collector walkthrough
-- To enable it, in Splunk Enterprise and self-service or trial Splunk Cloud, go to Settings > Data inputs > HTTP Event Collector.
However, what I see in Settings > Data inputs of our dev environment is -
What can it be?
Run the Add Data wizard and select HTTP Event Collector. If it has not been initialized, it should automatically take you to the overview page where you can enter the global settings.
After that, you can use the Add Data wizard to add tokens.
I had this problem once, and after I entered the global settings, the HTTP Event Collector showed up on the Settings >> Data Inputs page.
If that doesn't work, it might be something quirky. If a Splunk restart doesn't fix it, I would enter a support ticket.