Screenshots & the more detailed information you can provide makes it much easier for other players to be able to assist you.
The full correct name of the game scene/mine is extremely helpful.... otherwise other players can only give you generalised broad range suggestions.
Ok I think you are actually talking about Valentine 2020....not Valentine 2021 as you have put in your post title.
When you say about entering a keypad code I can think of 2 game scenes/mines in Valentine 2020 that use a number code.
1 is called Singleton Suburbs & the other is called Futurocity.
The maps are very useful for problems like that.
@Roeland makes very clear & concise maps that contain highlighted pictures & instructions....see attached picture
These maps are always available in the relevant Wiki page
And the maps are also available on @Abhi dedicated fan/player website that he created called Diggys Guide.
In relation to Singleton Suburbs check out this map
In relation to Futurocity check out this map
If you have a different problem.... please provide further & more detailed information.