Workflow for iOS: Adding first line as subject to E-mail.

iOS and iPadOS

Hello everyone,

I am new to workflow and I have been rummaging through the Reedits forum for this app, but I'm still having problems.
Basically, I want to get the first line of the body of an E-mail message and have it Pasted into the subject line (Seems simple enough).
I get stuck when setting variables because (1. Not sure if this is what I should be using to automate this task, and (2. When looking at examples it seems understandable enough, but still confusing when trying to apply the concepts for myself.

Any help would be greatly appreciated.