Because you have misspelt the endpoint in the URL ( serivces/collector ) instead of ( services/collector )
This is what you have:
https://prd-p-2lsvqbxyzzzzz.cloud.splunk.com:8088/serivces/collector
This is what it should be:
https://prd-p-2lsvqbxyzzzzz.cloud.splunk.com:8088/services/collector
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