Deploy app to google play

my question is related to app icon and screenshots required to deplopy my app to google play ,


1- I have 1024 x 1024 image for app icon and I set is using key
icon in app.json , should I create new app icon with size 512 x 512 for android ? and if yes how to set it in app.json ?
2-how to take screenshorts that can be accepted for google play they require images with specific resolutions ?
3- how can I create app icon for android to be accepted by google play if image is not valid ?
thanks in advance