John G. Thank you! I'm almost done with that, but one thing I notice is the Span ID I'm reporting to is not the same as the Span ID I get when I copy span ID from the dashboard.
# Get the span ID for Phoenix annotations
span_context = span.get_span_context()
span_id = span_context.span_id
# Convert span_id to hex string format expected by Phoenix
span_id_hex = format(span_id, '032x')