Won't let me erase hard drive to reformat to APFS
I'm trying to install Catalina. My hard drive (Macbook Pro 2017) did not reformat when I installed Mojave. I've backed up in two locations and ready to reformat to APFS. But when I go into Disk Utility it won't let me erase the drive. Is there a step I'm missing?
MacBook Pro 13″, macOS 10.14