Once you activate a trial period or purchase a subscription, all premium options disappear from the Premium screen in the 1Blocker app. While monthly and yearly options remain available in the App Store's subscription list, the Lifetime license is not displayed there.
If you decide to switch to the Lifetime membership during your free trial or subscription period, there are two ways to do that:
Cancel your current 1Blocker subscription from your list of Apple subscriptions and wait until the premium period is over.
Approach Apple to refund the current subscription. This option is recommended if you've recently activated your Premium, as Apple is more likely to approve the refund in this case.
Once the subscription expires or is refunded, the Lifetime plan will appear on the app's Premium screen alongside other 1Blocker Premium options.
It's worth noting that canceling your free trial or subscription opts you out of renewing it at the end of the current period. Premium features will still remain active until the current Premium period expires.