How to send data to opentelemetry in langflow?

[hawksung1]

I want to connect opentelemetry with my langflow.
I set env like

OTEL_EXPORTER_OTLP_ENDPOINT=http://****
OTEL_EXPORTER_OTLP_PROTOCOL=grpc
OTEL_EXPORTER_OTLP_TRACES_INSECURE=true
OTEL_SERVICE_NAME=test

but nothing sends to my open telemetry server.

How can I send span trace things to my opentelemetry server?