New Tablo DUAL OTA DVR - set up but want to add a hard drive

I’m loving the new Tablo DUAL OTA DVR. I’ve set it up, but now am finding I need an external drive for additional space. Wha are the steps to add a hard drive after I’ve already set it up without one? I ordered the a
western Digital 1T model recommended.

Just plug it in. 1 TB is a little small - can’t you double your space to 2 TB for like $5-10 more?

Got a great price for the 1T and we only get 3 of the 5 locals…so this should do us fine for now.