Reconnecting to my Mac

I recently moved and had to disconnect the components of My Mac.  After settling in and getting everything connected I thought all was fine.  Now, I needed to go back in my Time Machine and find that I was disconnected.  When I try to open the WD app, all I get is the message that I was disconnected on such and such a date. 

What do I do to get connected to my WD drive again and run my time machine?  Any help will be appreciated.

Sbsupt

And the model number of your drive is? Can’t help without this information :)…