need help with podcast
hello my name is alex so i want to post to podcast on itunes , and my host is soundcloud i got the rss feed which is this one http://feeds.soundcloud.com/users/soundcloud:users:88990581/sounds.rss
but it says "podcast artwork needs to be 1400 x 1400 and 3000 x 3000 pixels, jpg or png, in RGB color space and hosted on a server that allows HTTP head request."
i already contacted my designer for my podcast artwork to send me the higher pixel artwork & going to change them
what do i do next?
iMac (27-inch, Late 2013), iOS 8.4.1