Sorry you are facing this issue, it would be my pleasure to help you.
Welcome to the Shopify community!
Thanks for your good question.
Please share your site URL,
I will check out the issue and provide you a solution here.
My name is Lilith, I'm on the Social Care team at Shopify.
It sounds like you may be working with a developer to help you with your theme. If you're previewing the theme through your admin and close the preview bar, you can always regain that back by following some very simple steps:
1. Close the preview window you opened before.
2. Go to Online Store > Themes in your admin
3. Click on Actions > Edit Code beside the theme that you need to share a preview for
4. Click on Preview on the top right of that page
5. The preview bar will appear again and you can simply click on Share preview
As you work on your theme, I'd recommend keeping in mind that simplicity will be a key ingredient to your site's success. The easier it is for your customers to review and simplify their shopping experience the higher your conversion will be. If you want to try out a few things with your themes and you're a beginner, our DIY informative blog post will come in handy!
Don't be afraid to try things out, you can duplicate your themes and test things on your own without them publishing to the live site. It's a great way to get to know your store and the platform a bit better. Also, it will give you a great idea of what you may expect or request from your developer helping you out. The more you know about the inner workings of your store the easier it will be for you to manage projects surrounding your web design.
Let me know how you do with the information above! I'm happy to answer any questions you think of as you work on your business.
I checked and it still shows fine: https://i.imgur.com/Er1Ntdl.png
Can you send me the link &preview_theme_id, I will check it.