I see you are using the Divi Page Builder, which complicates things. There should be a way to set the Read More text within the builder settings. Normally we can do this with CSS with a bit of trickery, but we have to use a :before or :after pseudo selector, and in this case, both of those are used for the left/right border lines on the Read More.
The other way, if that is not an option in the Divi Page Builder, would be to create a Child Theme and then copy over the content.php file from the original theme to the child theme and then change “Read more” within that file.
