How to using *.qml file

[XuHg-zjcn]

QGIS version: 3.34.3-Prizren
OS: Trisquel 11.0 Aramo

I was read this guide, but it too rough, I can't follow the steps successfully.

after running ogr2ogr -f "SQLite" -dsco SPATIALITE=YES output.db input.osm, move "output.db" into QGIS window, and click button "Add Layers", layers "points, multilinestrings, lines, multipolygons" are single color.

Clicked Toolbar Select by Expression 'waterway'='riverbank', and click button "Select Features", show message "No matching features found" in view.

Clicked Menubar Setting->Style Manager->Import / Export->Import Item(s)->click three dots browse file, it only accept XML file, not QML file.

[anitagraser]

It has to be

"waterway"='riverbank'

As shown in the screenshot

[XuHg-zjcn]

I chosen data area different from guide, "waterway"='riverbank' not found, change to "waterway"='canal' found some lines, but I still don't know how to use qml files.
I see these files in the qgis2 folder, but I am not using QGIS2. Can these style using in QGIS3?