Application install failed - can someone please walk me through this ?

This looks like something that I would love to have, but after multiple attempts it keeps failing to install.

I am attempting to add it to Gimp 2.8.14

Thank you in advance.

Please, we are not clairvoyant.
What is the “it” you are trying to add to Gimp 2.8.14?
Where did you find that?
What did you try and what are the messages you got that make you think you fail?