You can add users to a Managed Progress Board.

This article explains how to add people who already have Makerble Accounts
To invite completely new people to join a Progress Board, use this article instead https://makerble.atlassian.net/wiki/spaces/MCPD/pages/1969225730

Steps

Only Board Admins can add users to a Managed Progress Board

From the Manage Progress Boards page

Select Impact in the left sidebar and choose Progress Boards
You arrive on the Manage Progress Boards page
Scroll down to load all the Progress Boards you have access to
In Cards view: Click Edit in the card for a Progress Board
You arrive on the Edit page in the Basic Information tab
Select the Colleagues tab
In the Members text field: search for the users you want to add and then click Next (Save)
You arrive on the Preferences tab. Click Save & Finish.

Select My Apps in the top menu
Place your mouse over the Boards button
A list of Boards appears
Scroll down and select the Board you want to add people to
You arrive on the Board’s page
Select the About toggle
The Colleagues box will appear
Press the Add New button in the box
A popup launches in which you can add the names of new users
Press save
The popup closes and the newly added users will receive an email telling them that they now have access to this board at the permission level you chose; either Board Admins or Board Colleagues