Question about 1D Blendspace holding down a key

I have a blendspace animation that a character is raising up its hand over time. I have set a hold down key to trigger animation, but the problem is I don’t know how exactly I can do to let my character fully raise up its hand. This is not IdleWalkRun that I cannot use character velocity in this case. How I should do?

this is the album with all print screen if it might help