webgl MovieTextures for safari

Hi,

w are using simple "Simple MovieTextures for Unity WebGL" and it works fine on chrome and firefox but it doesn't work at all on safari , mainly the video not showing

we tried the solution here :
https://forum.unity3d.com/threads/webgl-invalid_value-teximage2d-no-video.284926/

but it just showed black screen . and we were using WebM file format to test on safari

thanks