Hi,
Cloud you please send me your bank details for your expense payment
I read this as asking me for details of my bank account, so that a payment can be sent direct to my bank. It sounds a bit odd to me, as in my experience such one-time payments are not handled in this way, but anyway, assuming that's correct, I'd say something like this:
Could you please send me your banking information so that I can process your expense payment?
Best wishes, Clive