Hi there! Thanks for asking a question here on Brainly. ✉
The correct form of verb for the sentence would be to use the word are since the sentence is talking about multiple directions.
Answer: Where on my Internet browser are the directions to block pop-up messages?
Hope that helps! ★ If you have further questions about this question or need more help, feel free to comment below or leave me a PM. -UnicornFudge aka Nadia