Thanks a lot!
From what I see, you animated properties of modifiers that are not exported into FBX. In fact, you loose all animations such as the ones applied on "Bend" modifiers or the one applied to the "Spline Wrap" of your faixa (Plane) object.
The FBX specification doesn't handle such software specific modifiers, so Cinema4D can't actually export their effect in the output file. This happend with almost all 3D Softwares.
To allow this, Cinema4d has a "PLA to Vertex Cache" option which "bake" the modifiers effect into an external file, that is then attached to the FBX. Unfortunately, Sketchfab doesn't support this kind of animation data for now, so I am afraid you can't get it working using this method.
A possible workaround for this would be to generate morph animation from these modifiers, that is supported by Sketchfab. Cinema4d might include a tool to perform such a conversion, but I don't have anything in mind.
The state of your object will be the same as it was when you exported the FBX (if it was bent at the moment of the export, it will be bent in the FBX and then on Sketchfab).
Sorry for the bad news I hope you 'll find a way to get it working. If I have anything that can help, I will be back to you.
Have a nice day!