This model can make a flower blooming animation by using "Morpher" (or "Blend Shape" , "Shrinkwrap" ... or something else ) modifier.
And unfortunately, I don't know how to export a perfect FBX file that it can show the animation correctly on Sketchfab.
So I put my original animation "FBX" flie and morphing model "OBJ" file to the Additional files.
I also created my own flowers blooming animation on Youtube, Please refer to it:
https://youtu.be/XFDXK1HklIs