I've installed Prometheus on same server having signoz, enabled it on port 8888 In file deploy/docker/clickhouse-setup/otel-collector-config.yaml, Prometheus is enabled on port 8888 as well. From my code as shared below, I've enabled prometheus to recive metrics but in signoz the metrics are not visible while creating dashboard.

import { getNodeAutoInstrumentations } from '@opentelemetry/auto-instrumentations-node';
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';
import { Resource } from '@opentelemetry/resources';
import * as opentelemetry from '@opentelemetry/sdk-node';
import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
import { vars } from '../vars';
import { PrometheusExporter } from '@opentelemetry/exporter-prometheus';
import { PeriodicExportingMetricReader } from '@opentelemetry/sdk-metrics';


const oltpExporter = new OTLPTraceExporter({
  url: `${vars.otlp_trace_collector_url}/v1/traces`,
});

const exporter = new PrometheusExporter({
  endpoint: `${vars.otlp_metric_collector_url}/metrics`,
});

const otelSDK = new opentelemetry.NodeSDK({
  traceExporter: oltpExporter,
  // @ts-ignore
  metricReader: new PeriodicExportingMetricReader({
    // @ts-ignore
    exporter,
  }),
  instrumentations: [getNodeAutoInstrumentations({
    '@opentelemetry/instrumentation-fs': {
      enabled: false,
    },
  })],
  resource: new Resource({
    [SemanticResourceAttributes.SERVICE_NAME]: 'testing-backend',
  }),
});


export { otelSDK };

I don't think prometheus exporter works that way in OTEL SDK.