You can create quests in your mod by using Quest Framework. It is an easy way to create quests that the player(s) can fulfill for NPCs. You specify certain properties in a json (much like using Json Assets) and the framework interprets your specifications to create the code for you.
How to create a quest: https://questframework.purrplingcat.com/docs/content-pack-guide.html
Pages in category "Quest Framework"
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