Multiple

https://stackoverflow.com/questions/52952805/register-multiple-blackbox-exporters-in-one-job-in-prometheus

scrape_configs:
 - job_name: probe
   params:
     module:
      - http_2xx
     target: 
      - http://xyz/api/serverping
   metrics_path: /probe
   scheme: http
   static_configs:
    - targets:
       - bbexporter1:9115
       - bbexporter2:9115
       - bbexporter3:9115
       - bbexporter4:9115
       - bbexporter5:9115

curl "http://192.x.x.x:9115/probe?target=https://google.com&module=http_2xx"

Multiple URLs

scrape_configs:
  - job_name: 'blackbox'
    metrics_path: /probe
    params:
      module: [http_2xx]  # Look for a HTTP 200 response.
    static_configs:
      - targets:
        - http://prometheus.io    # Probe with http.
        - https://prometheus.io   # Probe with https.
        - http://example.com:8080 # Probe with http on port 8080.
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: 127.0.0.1:9115  # Blackbox exporter's address.