Attachments are files that can be created and read as a string in the op they are attached to.
An attachment file can be created by clicking on an op and then clicking the create button
Fill in the name of your attachment file
You can edit the attachment file by clicking on the edit button
This will open the editor allowing you to add your own script
The attachment can now be accessed inside of your op, select the op and press 'e' to enter edit mode.