3.1.10.1.5. OTP
From the OTP tab, you can enable or disable sending QR One Time Passwords (OTP) Secrets by email.
General

Enable “Send OTP secret as QR”: Select “yes” so that the user will receive a QR code that they will use in Google Authenticator.
Allow to send QR more than once: By default, the QR Code can be sent only once (if you want to send another email you have to generate a new OTP secret). In case you want to reuse the same code, enable this field.
One time QR: If we enable one time QR mode, the QR will adopt the following parameters:
TTL one time QR (in minutes): Defines the time in minutes that it will take for a QR image to expire from when it is sent until it is scanned by the user. By default 480 minutes.
Maximum number of uses of QR image: Set the maximum number of scans of the same QR image.
Captive portal URL: Address for the unique QR.
E-mail configuration
Email settings without one-time QR mode enabled.

Email QR from: Enter the e-mail address of the sender.
Username of “E-mail from”: Provide a descriptive name (e.g., the sender’s name or the organization’s name) instead of an email address, especially avoiding the same email address used in the “Email from:” field. This information is crucial to prevent potential rejection by mail relay servers due to anti-spam rules.
E-mail title: Enter subject of the email.
Email QR template: This section includes the HTML code that will be seen in the content of the email sent with the one time QR off mode.
One time QR email configuration:
Mail setup with single QR mode enabled.

Email from: Enter the e-mail address of the sender.
Username of “E-mail from”: Provide a descriptive name (e.g., the sender’s name or the organization’s name) instead of an email address, especially avoiding the same email address used in the “Email from:” field. This information is crucial to prevent potential rejection by mail relay servers due to anti-spam rules.
E-mail title: Enter subject of the email.
Email template: This section includes the HTML code that will be seen in the content of the email sent with the mode once QR enabled.
Click on Save to apply the changes.