Im making an update to my game and one of the features in the update are quests can anybody show me how to make quests please?

That's a very general question.
Coding quests depends on the structure of your game. I really don't know how to help you without knowing more.

As for making up quests (and achievements), I recommend goals that make the player do new things and that promote an interesting gameplay experience. For example, a good quest in Minecraft could be to trade with a piglin for a specific item. This forces the player to explore the dangerous Nether dimension, which can be both fun and risky at the same time.
Sorry if that's not what you asked, but I had to put something…

Oh I got it

when green flag clicked
if <1M Dollars> then
Achivement unlocked!
end

There you go! Lmk if you have any other questions.