Not able to authenticate on the P365 apps page "You are not authorized to access this page. Forbidden (403)" (4317266)

When the user log in to Power365 page, the following error message displayed as follow:
You are not authorized to access this page.
Forbidden (403)

The log in user email address not yet created in Power365 under this Power365 Client Name or this user does not hold either client administrator, power user or operator role for this specific client.

For example:

Power365 Client Name: ABC

User Email Address: John.Doe@abc.com

Verify the user exist in access + roles view

1. Click on Hamburger menu -> Manage -> Access + Roles
2. Enter User email address at search bar
3. Click Search.

Add new Client Administrator for this Client Name

1. Click on Hamburger menu | Manage | Access + Roles
2. Click "Add User" Button
3. Enter the following
   • User email address
   • First Name
   • Last Name
   • Select the Power365 Client this user been assigned to
   • The user roles
4. Click "Create"
5. User should log in again and he/she should be able to see Power365 UI.