PNG images do not have checkbox Transparent

I have tried to set transparent image in the PNG format.

Please find specifications and image.
Which setting blocks PNG image to be transparent checkbox as active checkbox?

I have clicked Export PNG > colour depth is True colour and Bitmap size 96 DPI > Options is not possible to be checked as Transparent.

You need to export as True Colour and Alpha

Unless your image is very large, use the TrueColor + Alpha setting.

And for the background to be transparent, there needs to be no background. So for the attached image just select the rectangle and the text.

TrueColor + Alpha has more color depth and produces a much cleaner image.