Doing giveaway to get more subscribers for my channel;

roofies?

You can request they subscribe but there's no feasible way to enforce it.

What about... I don't know, maybe make some interesting videos so people can subscribe to your channel because they like it?

Crazy idea, I know :)

The only way you can guarantee it is to set up private giveaways and give the links to your subscribers.

You cannot require any specific action from the users for their entry to be considered valid.
You can advertise your channel in your giveaways though (but you can't advertise in the forum, so I suggest removing the link form your post)

u tried streaming on twitch?

Why to subscribers to your channel?

For clips that last 1-2 min ? lel

you can use this https://gleam.io/app/competitions it will require them to follow all steps to join ga. but I dont know if you can advertise it here. hope someone will answer it :)