Grafana + Nagios

I started using Grafana and i have problem with connect nagios to grafana. I Install Nagios, PNP4Nagios and Grafana in one sever as here
When i loggin to grafana i see PNP, i put there URL: http://localhost/pnp4nagios and i have in the screen something like: HTTP Error Internal Server Error
In /var/log/grafana/grafana.log i have: t=2020-05-13T10:57:41+0200 lvl=eror msg=“Request Completed” logger=context userId=1 orgId=1 uname=admin method=GET path=/api/datasources/proxy/1/index.php/api status=500 remote_addr= time_ms=7 size=2256 referer=

Can someone help me configure this? Where i make mistake?