glTF is a modern 3D scene format for web and application pipelines. It can use external BIN and texture files, so conversion results are often safest as an archive.
Below are online converters for GLTF: convert GLTF files to other formats or create GLTF from compatible source files.
This converter shows the accepted source formats and the result format.
A damaged file or a non-standard codec can still fail even when the extension is supported.