Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
How far has the divorce reached?
Then at present the best you can do is have a Separation Agreement setting out the financial agreement.
To have a chance of being binding this should be signed after you have each had separate independent legal advice
There is a template here to give you an idea of contents
When you are dealing with the divorce you can turn it into a Clean Break Consent Order and have it sealed by the court - only then it is it totally binding
I hope that this is of assistance - please ask if you need further details
It is the only way available