To everyone saying 'oh, he might not remember nappies/potties/toothbrushes etc - this man decided months ago to leave his wife and 4 children, and move out.
He has also insisted that he wants 50:50 custody of the kids (although is nowhere near that so far, and we all know is highly unlikely to stick to it going forward).
He's had weeks and weeks to think about and plan for this.
It should not be up to OP to provide or remind him about anything.
He can use Deliveroo on Friday for anything essential they need that he's forgotten, and go to the shops to buy anything else on Saturday.
If he hasn't got enough money left he'll have to use a credit card or, the ultimate humiliation, ask his mum to help.
(And maybe reconsider the ££ he spent on that tattoo that he 'just had to have').
I'm glad you've got a fun outing with your friends to look forward to, @mummy917