I hope you are well today and thank you for your question.
You can change it by translating the theme as described here https://support.shufflehound.com/theme-translation/ or using any of the following plugins to change it.
thanks. I have installed Say What and tried to follow a tutorial however its not working. Can you please take a look?
If it is not working for you then please contact their support on the below page to make it work.