Hello @nikki.love,
My name is Henry and I am happy to assist with your inquiry, and appreciate you contacting LastPass Support!
I am sorry about the issues you are having with the extension. You can actually disable autofill for specific sites by setting them as Never URLs. Regarding re-prompt, you can only turn it on for specific items or turn it on for all of them. There is no setting to enable it for all items and add one as an exception if that is what you were looking for. You can see the instructions for both settings on this article.
Please let me know if this worked or if further assistance is required.
Thank you,
Henry | Customer Care