I see there is an SEO friendly landing page for this here - https://elfsight.com/content-locker-widget/
Would love for this to be made as we are now using webflow for our website and have no way to make this happen without the help of elfsight.
Previously I used a wordpress plugins to acheieve this. Here is the info on that in case it helps you and your team with planning and programing, etc.
They make two lockers - Social locker allows content to be unlocked by sharing about it, etc. The one we use on our site is their Opt-in Panda plugin that requires email sign up via manual entry, Facebook connection, linked in connection, gmail login or similar.
There is even a non-wordpress version of the social locker available here - https://codecanyon.net/item/social-locker-for-jquery/3408941?s_rank=4
Hope that helps and all the best.