Filter in WMS servering by QGIS Server

Full query

https://geoviet_mapserv.dothanhlong.org/?MAP=/gis/mbgis/api.qgs&service=WMS&request=GetMap&layers=vn_vunghanhchinh&styles=&format=image%2Fpng&transparent=true&version=1.1.1&tiled=true&width=256&height=256&srs=EPSG%3A3857&bbox=11897270.578531114,1252344.2714243277,12523442.714243278,1878516.4071364922

Filter query

https://geoviet_mapserv.dothanhlong.org/?MAP=/gis/mbgis/api.qgs&service=WMS&request=GetMap&layers=vn_vunghanhchinh&styles=&format=image/png&transparent=true&version=1.1.1&tiled=true&width=256&height=256&srs=EPSG:3857&bbox=11897270.578531114,1252344.2714243277,12523442.714243278,1878516.4071364922&filter=vn_vunghanhchinh: "ten_vi" = 'Phú Yên'

Refernces

https://docs.qgis.org/3.22/en/docs/server_manual/services/wms.html