https://www.htmlvalidator.com/current/d ... _using.htm
In step 8 (the step where you set up the job options in the Batch Wizard Options), be sure to select the 'Spell check' tool as the 'Tool to Use'.
That's it.
If you want to get "advanced", you can use the onMisspelledWord() function to exclude certain words.
You can also use special comments to turn off spell checking for parts of a document (<!--chvignorespelling--> ... <!--/chvignorespelling-->), or to specify words to ignore on a per-document basis (<!--chvignorewords word1,word2,word3-->). For more information see the Spell Checking documentation page.