This my configuration & working with splunk enterprise.

exporters:
  logging:
    verbosity: normal
  splunk_hec:
    token: "${SPLUNK_HEC_TOKEN}"
    endpoint: "${SPLUNK_HEC_URL}"
    source: "otel-db"
    sourcetype: "otel-db"
    profiling_data_enabled: false
    tls:
      insecure_skip_verify: true