Feedback: /deploy/early-access/reference/observability/ - Needs Improvement

## Documentation Feedback

**Path:** /deploy/early-access/reference/observability/
**Helpful:** No ❌

**Feedback:**
> It says I can add manual metrics

> Manually through custom instrumentation: Your application code can create new traces or spans using the OpenTelemetry API.

I do this, but i don't know how to associate my tracer with deno deploy EA:
```
import { trace } from "npm:@opentelemetry/api@1";
import denoJson from "@/deno.json" with { type: "json" };
export const appTracer = trace.getTracer(denoJson.name, denoJson.version);

// in another file (shortened for this issue)
appTracer.startActiveSpan("my-span", (span) => {
const authType = "Bearer";
if (authType !== "Basic") {
span.setStatus({
code: SpanStatusCode.ERROR,
message: "Unauthorized - Authorization header type is not 'Basic' Auth",
});
span.end();
return new Response("Unauthorized", {
status: 401,
});
}
})
```

I'd expect to see this custom span in my "traces" view on deno deploy ea, but i only see requests there.

**GitHub User:** @bjesuiter

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*This issue was automatically created from the documentation feedback system.*