How do I correct the timezone of $__timeFilter

I’m using grafana to connect the postgreSQL. Local server and brower are using UTC+8.
and set the grafana config timezone to brower.

When I using where $__timeFilter in grafana, the actual datetime is always UTC+0.
For example, in the grafana GUI, I select time range from
2022-09-18 08:00:00 to 2022-09-19 08:00:00,
but the actual SQL is: 2022-09-18 00:00:00 to 2022-09-19 00:00:00,

How do I make sure grafana use UTC+8? in $__timeFilter, etc.