Forcing Backup Across Linux and FAT Partitions

Greetings,

I have a USB HD with two partitions, the boot one in linux Mint Petra (32bit) ext4 and the other FAT32 with my main work files on it. I set up Deja Dup to auto backup .config and .cache folders in the linux partition and to archive them in the FAT partition which gets automatic full cloud backup. I found that I'm unable to jumpstart Deja Dup after it's made its first daily run in case I have another folder for it backup the same day. How can I force Deja Dup to backup on demand?

Thanks & keep up the great work!

JIm in NYC