How to: Create dynamic function output

Create the function

UFUNCTION(BlueprintCallable)
void FunctionName(TSubclassOf<UTemplateClass> TemplateClass, UTemplateClass*& TemplateClassOutput);

Add DeterminesOutputType and DynamicOutputParam specifier

UFUNCTION(BlueprintCallable, meta = (DeterminesOutputType = "TemplateClass", DynamicOutputParam = "TemplateClassOutput"))
void FunctionName(TSubclassOf<UTemplateClass> TemplateClass, UTemplateClass*& TemplateClassOutput);