Hi there 
I don’t know why my checkout button is not showing up. The second photo is not mine. I’ve tried looking through forums but I can’t seem to find the solution.
Thank you,
Sophie
Hey, there!
Jason here from Shopify Support.
Great question! If you’re using one of the Shopify themes, the checkout button is always going to show up unless you’ve done some customization through the code. A great way to check if it’s related to the theme or perhaps a disruption through the apps is to simply download another copy of the same theme. Check if the checkout button is there. If it is, then it’s theme code related. If it isn’t, then most likely related to an app that you recently installed.
If you’ve made code customization causing the checkout button being disappeared accidentally, here’s a useful document on how to roll back to an older version for your theme. From Shopify admin > Online Store > Themes > Actions > Edit Code:
If you’re using a third-party developed theme, I recommend troubleshooting it through the steps above first to determine where the issue is. Feel free to reach out to the theme developer support and ask for assistance. You can find out who developed your theme from Shopify admin > Online Store > Themes > Customize. In the theme editor, on the left-hand side menu, if the theme’s updated, click on Theme settings. Scroll down to the bottom and you’ll see the theme developer’s contact. If the Theme settings section isn’t available, meaning most likely the theme’s outdated, simply scroll down to the bottom and you’ll be able to find the theme developer’s contact at the end.
There’s a chance you may not be able to get a hold of the theme developer support. With that being the case, feel free to contact one of the Shopify Experts. The designers there will be able to assist you on this restoration.
I hope this information helps, however, should you have any questions, please don’t hesitate to reply back here and I’d be happy to help out!
All the best,
Jason
What part of the code would it likely be under and what would it look like? Would it have the word checkout or something like that? Because I have edited the code so much that I can’t tell what to version to use, plus if I switch versions it changes stuff that I want to keep.