gif
convert -size 1080x1080 -delay 20 -dispose previous -loop 0 -layers Optimize -transparent *.png 000.gif
Reference:
https://imagemagick.org/script/command-line-options.php#background
https://legacy.imagemagick.org/Usage/anim_opt/
https://legacy.imagemagick.org/Usage/quantize/#colors
https://webinista.com/updates/how-to-create-animated-gifs-imagemagick/
http://shebangthedolphins.net/gnulinux_ultimate_gif_tutorial.html