I am unable to login to bitbucket

[Anitha Thangakrishnan]

Bitbucket is unable to reset the password for your account because it is managed by a read-only external directory. Please contact your administrator to change your password.

[Nic Brough -Adaptavist-]

This is exactly what it says it is, your Bitbucket account is managed in an external directory (Okta, LDAP, AD etc), so you can't change the password in Bitbucket, you need to do it in that directory.

You'll need to talk to your user administrators (not your Bitbucket admins, although they should know who your user administrators are, or where your reset processes are docuemented)