You're on the right track. All you need to do is use the For Each action with the Finders Selection collection to make the selected file (specifically, its path) into a variable, then use that variable with the Send Mail action, like this:
This can only be used to attach one file per message (if you want to attach multiple files, you need to look into using AppleScript) but if one file is all you need, this should do the trick.
Ahh. I misunderstood. When you said "when I get an invoice" I thought you meant via an incoming email. I thought you meant getting invoices sent to you in an email. Sorry.
Hey [quote="Anders_Kristensen, post:1, topic:14653"]
I want to add a hot key for when I get an invoice PDF, so I can send it to the payment system via email
[/quote]
Hey Anders,
Welcome to the Keyboard Maestro forum!
What mail client are you using?
If you haven't read this it's worth a couple of minutes of your time.