Paste image with transparent layer

paste image with transparent layer becomes with white layer
i use GIF format how can i paste it with transparent layer

Krita doesn’t work with .gif images. If you have an original .gif image with transparency, I suggest that you Open it with GIMP and Export it as a .png, then use the .png file.
Exporting as .gif from inside krita gives dithering (even if it’s not needed) so for .gif work you’re better off using GIMP.
For work that you feel needs the use of krita, use the .png conversion via GIMP method.

1000 thanks for the help