Tracing datadog

Hi,

I'm using traefik with kubernetes.

I want to use traefik trace with datadog but I keep get this error

[traefik-f8cc6cb87-znzj9] time="2020-02-02T15:07:07Z" level=debug msg="Failed to extract the context: span context not found" middlewareName=tracing middlewareType=TracingEntryPoint

Traefik config:

additionalArguments:
  - "--entryPoints.web.forwardedHeaders.insecure"
  - "--api.insecure=true"
  - "--accesslog=true"
  - "--tracing=true"
  - "--tracing.serviceName=traefik"
  - "--tracing.spanNameLimit=15000"
  - "--tracing.datadog=true"
  - "--tracing.datadog.globalTag=devops"
  - "--tracing.datadog.localAgentHostPort=datadog:8126"
  - "--metrics=true"
  - "--metrics.datadog=true"
  - "--metrics.datadog.address=datadog:8125"
  - "--metrics.datadog.addServicesLabels=true"
  - "--metrics.datadog.pushInterval=10s"

Can you tell me what should I do?