We released a notarized version of Axure RP 9 that should help to get past the security prompts from macOS 10.15 for users for whom the steps above weren’t working. The link and details on how to get past this are noted in the post below:
That should do the trick, but for anyone still running into issues after downloading the notarized build then please email support@axure.com and note the steps you’ve tried so far so that we can assist. Thanks!