You can use the "Forgot password?" link to self-reset your password in Plex if your Plex account has been setup with a valid email address under your Plex profile
If you forget your password, do the following:
1. Log in to IAM with your account at https://accounts.plex.com.
2. Type your Username, and Company Code.
3. Click the Forget password? link.
4. On the Reset Password dialog, type your Username and Company Code.
5. Click Submit. A message with information about the password reset is displayed.
6. Check your email and follow the instructions to reset your password.