UE4 - Get children widgets from UUserWidget's pointer (UMG)

I got my non-UObject class holds an

UUserWidget* Instance;

So how do I get a children widget (Ex: UTextBlock) out of that

Briefly, I want something like this: Instance->GetChildrenWidgetByName("UTextBlock_Name")

In 4.26.2 you can do this if you know the child's name

Instance->WidgetTree->FindWidget(WidgetFName);

or this if you just want to find it by type

TArray<UWidget*> Children;
Instance->WidgetTree->GetAllWidgets(Children);
for(auto Child : Children)
{
    if(UTextBlock* Block = Cast<UTextBlock>(Child))
    {
       //return Block
       //or add to some TArray if you want to find multiple
    }
}

for more information take a look into documentation

on a side note a very handy way of getting pointers to children of a widget is to use meta = (BindWidget) in UPROPERTY - more on that here