Describe the bug
There is an error when a user click on 'My Account' then click on 'Notifications settings'.

To Reproduce
Steps to reproduce the behavior:

1. Log into an account
2. Click on 'My Account'
3. Click on 'Notifications settings'
4. See error

Expected behavior
The user should be able to see his Notifications settings from his account.

Screenshots

Click on 'My Account'

Click on 'Notifications settings'

See error on try.decidim.org

See a more verbose error

The error seems to be related to the VAPID KEYS used for notifications push.
I have generated the VAPID KEYS with rails decidim:pwa:generate_vapid_keys like it is said in this document https://github.com/decidim/decidim/blob/v0.27.1/docs/modules/configure/pages/environment_variables.adoc but the error remain.

Stacktrace
If applicable, add the error stacktrace to help explain your problem.

Extra data (please complete the following information):

• Device: Desktop
• Device OS: Windows 10
• Browser: Chrome
• Decidim Version: 0.27.1 and try.decidim.org

Additional context
Add any other context about the problem here. For instance, add Metadecidim link.