@Truffles_13 I still think this one is the best you can do right now:
https://www.box.co.uk/FX505DD-BQ121T-ASUS-FX505DD-BQ121T_2902781.html
It has a nice enough screen and plenty of storage, plus room for extra RAM if you decide you want more later. You're unlikely to do better for an equal price.
Laptops with the newer and faster Nvidia 1650 graphics card are £700 and up, although I did see one for £680. But it's not worth straining your budget that much. The Nvidia 1050 in the one above will handle ultra graphics settings now, even if you have all the packs. Worst case scenario, you'd eventually need to play on high instead of ultra, but that's not a bad outcome at all.
I checked the usual sites and only saw one other laptop in your price range, this one for £650. Its graphics card is a 1050 ti, faster than the normal 1050 but slower than a 1650.
https://www.box.co.uk/8PL55EAABU-HP-Pavilion-Gaming-15-cx0019na_2891397.html
Sure, it would run Sims 4 on ultra settings for longer, but it's probably also not worth the extra cost if the £50 would make a difference to you. Really, the important distinction is between laptops built for gaming, as these are, and the next tier down. The £600 Asus should be fine for what you want out of it.