Why few keys in redis has no TTL?

Hey im noticing many keys are there in redis which has no TTL, so it stays forever, session information will be expiry after 30 days, Im using secondary database as redis by passing secondaryStorage: { get: async (key) => { const value = await redis.get(key); return value ? value : null; }, set: async (key, value, ttl) => { if (ttl) await redis.set(key, value, ttl); else await redis.set(key, value); }, delete: async (key) => { await redis.delete(key); }, }, to auth Just need to understand how to add ttl to this? and is it bug? because of this redis is getting huge amout of data, even when this is used? 😕