I have prepared this tutorial to download Cisco cloud router IOS XE which is the same software for ASR1K and ASR 900 and how to integrate it to teh GNS3, Hope the video is good and informative for you.
<span style="color: rgb(119, 119, 119); font-family: acumin-pro, "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 15px;">[video]
https://youtu.be/AusnenCfvxI[/video]