I want to use the WEBGL_draw_buffers extension. Besides enabling the extension by gl.getExtension('WEBGL_draw_buffers'); in the JavaScript, one apparently has to enable the extension in the shader as well by using the directive #extension GL_EXT_draw_buffers : require. However, whereas my WebGL implementation seems to support the WEBGL_draw_buffers extension (also according to WebGL Extension Viewer), the shader does not. I'm getting the following error:
'GL_EXT_draw_buffers' : extension is not supported
Is there a way to fix this? I already updated my graphics card driver. I get the error both, with a dedicated AMD Graphics Card (that also supports OpenGL 4.5) and with an integrated Intel Graphics Chip.