Grafana No Data Points (Prometheus database type)

Hi all, I am a new user of Prometheus and Grafana tools. have installed and configured the Prometheus server and scraping the metrics from the exporter (Nvidia TensorRT Inference Server). In fact, I was able to see the plots of the metrics via the web browser with Prometheus.

On another hand, I have installed Grafana 6.1, configurated the data source (it passed the connection test) and imported a pre-built dashboard from, but the plots are empty showing the messages “No Data Points”

Some tips to fix it?