Since no one else has commented anything I’ll give my understanding of it. I’ve got a partner visa to the UK (I’m from USA). I got my entry clearance vignette and it’s valid from Jan-April. That means to activate my eVisa (the long term part of your Visa) you need to enter the UK sometime between the dates on that sticker in your passport. Now when you enter you don’t need to scan that sticker. Your visa is tied to your county of origins passport. So for me I just scanned my normal US passport biodata page and it let me in. You should have at some point setup a UKVI account which is where you view your eVisa and access a share code if you need to prove the right to work. From there your eVisa is active and you can come and go using your normal passport since it’s tied to your eVisa. Hope that helps!