I have a script that generate two different e-mails, one with the attachment and one that contains the e-mail address. Has anyone an idea on how to get them combine somehow so that just one e-mail would be generated?

Go to layout ["Faktura" (KSF medlemslista)]
Save Records as PDF [Restore; "No dialog; "untitled.pdf"; Create email; Current record]
Send Mail [Send via E-mail Client; To: KSF medlemslista::e post: Subject: "KSF medlemsavgift 2020"; Message: "Medlemsfaktura som pdf bifogad”; "untitled.pdf")
Go to layout [original layout]

Save the PDF path in a variable and then use that variable in the Send Mail step.

Set Variable[ $path ; Get(DesktopPath ) & "untitled.pdf" ]
Save Records as PDF[ $path ]  // don't create email
Send Mail[ ... ; $path ]

Welcome to the forums!