Not any issue you can provide theme.js file here i will update code
There should be no need for the file or even your account details.
You can just search for 'theme.Quotes' (Cmd + F on Mac, Cntrl + F on Windows), find the similar code, and change the value for autoplay from false to true.
The code should look something like this:
Hopefully that helps!
Can you please add more testimonials currently only three.
Welcome to the Shopify community!
and Thanks for your Good question.
Please share your site URL,
So I will check and provide a solution here.