editing "Send To Option Tree" button

I wanted to edit the “Send To Option Tree” button that shows when you try to add an image. Like in the slider. I did a search and found the text in ot-functions-admin.php and I changed it to “Use This Image” but when I check, the uploader still says “Send To Option Tree”

What do I need to do to get OT to recognize this change?

https://www.ads-software.com/extend/plugins/option-tree/