@iftekhs Of course that won’t work. You can’t convert an SVG image to a valid PNG image just by base64-encoding it with the prefix png.
You’ll need to use ImageMagick or some similar image library to load the SVG file and convert that to a PNG file. That’s not particularly a Laravel issue, though, you can use any plain PHP for that (Googling “PHP convert SVG to PNG” will give you plenty of ways to do it).
But is there a reason why you want to turn an SVG into a PNG? If it’s a logo, and the original is SVG, why do you need a PNG?