1️⃣ Click on your Admin tab in Canvas.
2️⃣ Click the account in which your group is located from the list in the pop-out menu.
⚠️ Depending on your permissions you may see different accounts listed.
3️⃣ Click on People.
4️⃣ Click on the three-dot icon (to the right of the search people bar) and click View user groups in the pop-out menu.
5️⃣ Click the Group Set tab you want. Under the set, find the group to which you want to add people and click the small + icon. Then in the search people bar pop-out, type in the user's name you want to add. Click on the name that shows up in red to add that person to the group.