Backpack with detachable cross body bag

[crochetmonkey74]

I'm pretty sure I have dreamt this bag and it doesn't exist but I'd love a backpack with a detachable cross body bag.
Think - I'm going on the tube and want my phone and purse round me, but want my stuff for a day in London in my backpack. Then , later when I am at work, I can leave my backpack under my desk and just take my crossbody out to get a coffee. At weekends, I just use it as one bag when I'm off for a wander.
I don't want 2 separate bags, as that gets too bulky. I'd like one with a detachable one. I am sure that I saw one once in an Accessorize years ago but any of you lovely lot seen one?

I have this one from Amazon. The removable handbag is big enough to fit my phone, passport and a small purse. I use it a lot when on holiday.

Not sure what your budget is but there's this one from Sarah Haran which keeps popping up on my FB feed.

https://sarahharan.com/collections/backpacks/products/poppy-4-in-1-backpack-tote?variant=42293516566773

Desigual voyager - it's on my wishlist!
https://www.desigual.com/en_GB/search/?q=voyager