Step by Step instructions for extracting contacts from your iPhone into a file for Slick to import.
On your iPhone, go to Settings > [Your Name] > iCloud
Ensure that the "Contacts" entry is toggled on (you may need to merge your iPhone contacts with any existing iCloud contacts).
Next, log in to iCloud with your Apple ID from a browser on your computer.
You will be send an authentication code to your phone, please enter this.
Click the "Contacts" app icon.
Click the first contact, then do "Ctrl+A" on your keyboard to select all.
With all Contacts selected, click the cog icon in the bottom-left corner of the screen.
Hit "Export vCard..." to save contacts directly to your computer.