How to change "Devise: password reset instruction email's subject"

I'm just unable to change "password reset instruction" email's subject. I have changed notifer.rb in Mailer to overwrite Devise default email subject. But it's not working.

Here in my application there is default Email subject inside Devise .yml file. But I want to make it dynamic to change it by pulling data from DB.

you can change it in devise.en.yml file in intilizer directory

And set your own subject for any mailer

                   mailer:
                     confirmation_instructions:
                       subject: 'Confirmation instructions'
                     reset_password_instructions:
                       subject: 'Reset password instructions'
                     unlock_instructions:
                       subject: 'Unlock Instructions'