What is LP protect?
LP protect option hides your landing page from direct entries, including entries from spying tools (like Adplexity, etc.). At the same time, your landing page will be opened for new redirects. In practice, that means that a user will be able to visit the landing for 5 minutes. After that, the same user will not be able to do that.
Example
This is a direct tracking link (Click URL) which users can always have access to:
https://tracking.domain.com/5c5808c2ec173600012aa1da?sub1={pln}&sub2={uid}&sub3={crid}&sub4={plid}&sub5={campaign}&sub6={cc}&sub7={isp}&sub8={country}&sub9={ip}&ref_id={clickid}&cost=1
When you click on it, you are redirected to a page with a URL like this:
http://your-landing-page-url.com/?lpkey=ab53ff920f5569d54e6d5d0ecb803774.1549368473&rdtrckcbp=1549368173
However, when you try to access this page without a tracking link by сlicking http://your-landing-page-url.com, you will only see a blank page:
1. Add ?lpkeyua={lpkeyua} at the end of your landing page URL
2. Copy the LP protect script (it is the same for all of your landing pages) to your landing page body
Important note: your page should have a .php extension. Make sure your hosting supports .php.