How do I split the OutMappings struckt for GetAxisMappingsByName?

I am currently working on a keybinds system and need need the key type in the OutMappings struct of GetAxisMappingByname/GetActionMappingByName.
In order to get it I need to split the struct, but the engine does not allow me to do this.

I have read that I will need to go into the c++ files and manually alter the associated witht he functions, but I do not know how what to alter.

Does anyone know what I need to change?