Promotion pop-up - how to make it mandatory email input, and also disappear once email submitted rather than stay on screen....

Hi 

I'm reaching out for assistance with configuring a promotional pop-up on my Squarespace website, and I'd greatly appreciate some expertise as I'm a non-coder.

Here's what I'm looking to achieve:

1. Promotional Pop-up as a Lock Screen: I aim to implement a promotional pop-up that serves as a lock screen, requiring visitors to input their email address to unlock the content behind it.

2. Prevent Dismissal by Clicking Outside or Refreshing: I want to remove the ability for visitors to dismiss the pop-up by clicking outside of the box or refreshing the page. This ensures that they engage with the email submission form before accessing the content.

3. Post-Submit Message with Automatic Disappearance: Upon successful submission of their email address, I'd like to display a "Thanks and Welcome" message within the pop-up. This message should automatically disappear after 3-4 seconds, rather than requiring the visitor to click outside of it.

I've found various streams on Circle of people attempting a similar thing no one seems to have discovered a perfect solution and any of the code that's suggested hasn't worked for me.

If anyone in the forum has experience or expertise in configuring such pop-ups on Squarespace, I would be incredibly grateful for your guidance, tips, or code snippets to achieve these functionalities.

Thank you in advance!!

Sarah