I apologize in advance if this has already been asked. Since Expertflyer no longer is able to show Delta award/fare availability, is there any way to check to see if there is R availability on a flight other than calling DL?

I have a flight planned for this fall that I'm watching and would like to be able to see if R becomes available so that I can use one of the regional upgrade certificates. If anyone has any suggestions on how to check fare class availability outside of calling DL and could let me know it would be appreciated.

Thanks!