Let's say you want to put a shadow on the "P", "D", "rogressive" and "imension" parts. You can do the following
// text with shadow
text2png.replace('P','rogressive','D','imensions', {
'shadow_color':'#000000', // the shadow color defaults to black
'shadow_distance':10, // the distance in the shadow (set to zero to remove the shadow
'shadow_blur':5, // where the shadow start fading
'shadow_strength':50, // the opacity of the shadow
'shadow_angle':315 // the angle of the shadow (no comma after the last option)
});
// text without shadow
text2png.replace('invite','phone','tollfree','espanol','proud','copy','join','email','name','author2');