Error connecting to Loki data source msg "Loki: Bad Request. 400. Authentication to data source failed"

Hello

When i try to connect to Loki data store on the localhost as Grafana server i encounter the following error.

Please can you help me in solving this issue.

Thank you in advance.

Platform : VMware Workstation 16 Pro Version : 16.1.2
OS Version : Ubuntu Server 16.04.1 LTS
Grafana Version : 8.3.6
Loki Version :2.4.1
Promtail Version : 2.4.1