Its tricky. For a regular, no issue process, you must have the I-797 approval copy with your petition filing in order for you to consider your petition under non-CAP. BUT… there are cases where it was approved with partial information provided without the copy of receipt notice. Its up to the officer who is processing your petition with the information (like receipt number, validity dates of the approval etc) that you are able provide. But this is not guaranteed. At the same time its PERFECTLY legal to apply with the little known information, there will be no negative impact(as long as you didnt lie or misrepresent any fact in your petition).