A 404 error shows when a page is not found.
Sometimes this can be because a customer clicks on a link which leads nowhere, or maybe they have typed a URL manually, which then takes them to a non-existent part of your site.
You may have sent out a link to a product or page on social media and then at a later date, removed or altered the location of this.
When the customer hits that endpoint, where the location is no longer valid, they will see a 404 error - you can thus edit the text the customer sees here.
You can do this by heading to:
Online Store → Themes → Customize
Click on the drop-down page selector and choose “404 page”.
For changing the wording/text, this should be super-easy to do if you go to:
Online Store → Themes
Actions → Edit Languages
You can search in the box at the top for the existing text. It will then bring up result/s where you can edit this.
Any changes to the text here will be reflected on the storefront.
Alternatively, you can click the “general” tab and you will see the page text listed under “404”: