Magic links aren't designed for use in email campaigns. Because they expire after 3 minutes, they only work in real-time scenarios, not in emails that may be opened hours or days after they're sent. There are two better options depending on what you're trying to accomplish.
Option 1: Direct subscribers to their Customer Portal
If you want to send subscribers to their portal to manage their subscription, use the manageSubscriptionUrl variable in your Klaviyo email. This generates a personalized portal link for each subscriber.
Keep in mind that subscribers will still need to log in or confirm their identity once they land on the portal, this link just gets them there directly.
Learn more about Klaviyo event properties here.
Option 2: Use Quick Actions for specific tasks
If you want subscribers to take a specific action (like skipping an order, swapping a product, or reactivating a subscription) without logging in, use Quick Action links instead.
Quick Actions can bypass the login requirement entirely when authentication is turned off in your Quick Actions settings. Each link takes the subscriber directly to a confirmation page for the specific action you've configured.
Note: Skio's Klaviyo integration includes access tokens by default, so if authentication is enabled, subscribers who click a Quick Action link from a Klaviyo email will be authenticated automatically, no extra setup needed.