Unfortunately the volumetric effects of OpenVDB are not supported in any standard formats that I know of. The tools listed at https://www.openvdb.org/ (Blender, Octane, Arnold, Houdini) suggest it is mostly used for offline renders, and glTF features are much more focused on real-time rendering. So I don’t know of any automatic way to convert a VDB file to glTF.
There are ways to do fake volumetrics that could work in glTF — see https://sketchfab.com/3d-models/fluffy-cloud-2c887a28840f47cfae6b5dee0d11b842 for an example — but as the author mentions they’re pretty resource-intensive.
If no, do you have any ideas on how can I achieve that?
Are you trying to achieve realistic clouds by any means necessary, or does this specifically need to be exported to glTF? If you have the option of writing shaders, and are using an engine that supports volumetrics, like Unity, there may be engine-specific options available.