Perusall no longer supports Sign in with Twitter, but you can continue to access your Perusall account by adding a password. To do this:

1. Go to the login page and click Forgot Password.
2. Enter the email address associated with your Perusall account.
3. Check your email (including your Spam/Junk folder) for an email from Perusall with a link you can use to add a password to your account.

Once you have set a password, you can log in using your email address and the password you have created. If you do not know the email address associated with your Perusall account, contact Perusall Support.