Use Meta Specifier ExpandEnumAsExecs to expose an enum as multiple output exces

UFUNCTION(BlueprintCallable, meta = (ExpandEnumAsExecs = "EnumOutput"))
void FunctionName(EInventoryIsValid& EnumOutput);

void UClassName::FunctionName(EInventoryIsValid& EnumOutput)
{
	if (Something)
	{
		EnumOutput = EInventoryIsValid::NotValid;
		return;
	}
	
	EnumOutput = EInventoryIsValid::IsValid;
}

<aside> ⚠️

You need to include the Enum Header. Forward declarations wont work

</aside>