How can I edit my password protected page to collect emails?

[HappyHeart]

Hello. I am trying to edit my code for my password protected page, to collect emails, which would then trigger for my Klavijo email marketing to send out emails. They provided me with snippet to put in, however when I go to the password.liquid section under templates on my Shopify account, I do not see this as an option. I only see basic information. When I clicked under layout and selected password.liquid I seen the a snippet/input/password however I believe this was regarding the password for logging into my shopify account. I have included pictures below. If anyone can please help. I would greatly appreciate it. I plan to launch in two weeks. Thanks.  

[PaulNewton]

The second picture has storefront_password which is for the frontend and nothing to do with you logging into the admin.

Just backup the theme and try putting the providec code and making a test by filling out the form and submitting it.

Otherwise depending on theme the 1st image applies and you should look in section password-content etc.