Does ProWritingAid recognise my MS Word Custom Dictionary?

ProWritingAid doesn't access your Custom Dictionary in Word. To stop ProWritingAid from highlighting certain words as spelling errors, you'll need to add them to your ProWritingAid dictionary. 

You can find and edit your personal dictionary here: https://prowritingaid.com/en/App/Dictionary

To get to it, go to the ProWritingAid website, then click on your name. On the account page that opens, click on the three lines in the top right to open a menu, then click on 'Dictionary'. 

Here, you can see the words you've added to your dictionary, add more words and delete words you no longer require. Once words are added to your dictionary, ProWritingAid will not highlight them as spelling errors.