Message Box and handling attachments

Hello, i want to have a pop-up window in katalon recorder so i can store my variable which then can be used in a field which must be filled in later in my testcase. Is that possible?

I am also struggling with adding attachments into a changemanagement tool called maximo. I recorded this once but when i rerun it the path is changed to C:\Fakepath<attachmentname>. Is there a way to solve this? I am running this on a Macbook Pro.

Thanks in advance for any help.