I can't export .osm from openstreetmap

Every time I trying to export the an area of map, it exports it as .mxl so it not work on sketchUp. what’s the problem.
the second question is, I downloaded some osm such as asia-latest.osm.pbf and …, but I don’t know how to use them.

What are you actually trying to do?

Whatever it is, I’d suggest doing it with a very small area first. The whole of Asia is a 7.6 GB .osm.pbf (compressed) file; I’d suggest obtaining a very small portion first and experimenting with that.

When you export data from the OSM website you’ll get an uncompressed XML data file containing all the XML data in the area that you’re exporting from. Depending on what you want to do that might be what you want or it might not be. If you can explain in a bit more detail what it is that you are actually trying to do people may be able to help.

You mention Sketchup - a quick web search finds a few links that might be useful: https://duckduckgo.com/?q=openstreetmap+sketchup&t=ffsb&ia=web .

thanks for your attention;
Actually I sow a clip https://www.youtube.com/watch?v=KKUGAZXU4dY that insert a “osm” file in to the sketchUp and it turn the map to 3D. It’s awesome and it’s exactly what I want. When he export the map from openstreetmap, all his format are “osm” but mine are “xml” and “xml” not work as what I want. what I have to do and what’s my wrong?

*.osm files are in XML-format. At 3:12, I see that the person obtains an .osm-file as well.

Please note that this height of the buildings is not available around the world. The example in the video uses New York. In New York, this data was imported from government data.

But why I can’t export OSM???!!!

At this moment it works for me, i.e.
go to osm.org,
press export button above the map
then press the export button in the left panel.

You can only download small areas of data in the way I described.

You wrote that you downloaded an osm.pfb file, this is a different file format: https://wiki.openstreetmap.org/wiki/PBF_Format
vs. OSM XML: https://wiki.openstreetmap.org/wiki/OSM_XML

The OSM file format is simply custom XML. If the file you download has a .XML file extension, you can change it to .OSM and you now have an OSM file.