Uncaught SyntaxError on mobile-friendly test

The test gives an error: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode - Test results are available here.
If open at the source code of the page: view-source:https://outdoorsly.org/best-hiking-boots-under-100/
At the 259th line is the assignment of a variable.
However, there are no visual errors on the site.
Tell us what the problem may be and how to fix it?

The test doesn’t allow the let keyword to be used outside of strict mode.

You have two options. Either put the code in strict mode, or use var instead of let.

Thanks for the direction Paul, I will go to fix it.