Change the settings of the {{NEXT_PPPOE}} PPPoE session. The stored PAP/CHAP password is never shown; leave the password field blank to keep it.
Dial a PPPoE WAN session over a physical interface ({{NEXT_PPPOE}} is allocated automatically). The PAP/CHAP password is stored in the secret store and referenced by name — it is never shown again and never lands in the saved configuration.
secret:*:write. Your account has interface write but not secret write — choose None for authentication, or ask an administrator for secret write (net-admin role).