It lets you show a How to order <module>? button at the top of that module's ordering page which opens your own tutorial video in a pop-up. Paste the YouTube embed URL (the https://www.youtube.com/embed/... form, not the normal watch link). If the field is empty and Theme: Kitchen → Show 'How To' on website? is set to Yes (the default), Sprwt shows its own default tutorial video for that module instead; if both are off, no button is shown. The Subscription tab has two rows sharing the same label - one loads on the plan-choosing page and one on the meal-selection page.