The standard and most effective design for an invitation-based registration process in Power Pages (formerly Power Apps Portals) is to embed the unique invitation code directly into the URL of the registration link sent via email. When the user clicks this link, the portal's "Redeem Invitation" page automatically captures the code from the URL parameter. This streamlines the user experience by pre-populating the necessary field or bypassing the code entry step altogether, securely associating the new portal user with the corresponding Dataverse contact record.

A. The invitation code is used to initiate the registration (sign-up) process for a new user, not after an existing user has already logged in (signed-in).

B. This is a consequence of the correct design, not the design itself. Embedding the code in the URL (Option C) is the mechanism that enables auto-population. Also, redemption occurs on a sign-up or redeem page, not the sign-in screen.

D. Sending a username and temporary password in an email is a significant security risk, as email is not a secure channel. Best practices dictate that users should create their own passwords during a secure registration process.

1. Microsoft Learn. (2023). Invite contacts to your portal in Power Pages.

Section: "Send invitations"

Content: This document details the process of creating and sending invitations. It states

"The invitation contains a link to the portal and an invitation code... When you send an invitation through email

it contains a URL that the user can select to navigate to the portal." This confirms that the link itself is the primary vehicle for the invitation.

2. Microsoft Learn. (2023). Redeem an invitation in Power Pages.

Section: "Redeem an invitation"

Content: This guide explains the user's perspective. "When a user redeems an invitation code

they're redirected to the Sign up page to create a new account." The process is initiated by the user clicking the redemption link in the email

which contains the necessary information (the code) to identify the specific invitation. The URL structure is typically [Portal URL]/register/?invitation=[invitation code].

3. Microsoft Learn. (2023). Set up authentication in Power Pages.

Section: "Invitation-based registration"

Content: This documentation outlines invitation-based registration as a core authentication feature. The flow depends on a unique invitation code being sent to a contact

which is then redeemed to create a user account. Embedding the code in the URL is the standard implementation for this feature.