Step by step:
Click on the “Contacts” tab.
Click on the simplified client list.
Select the picture of each wanted client to select them specifically.***
Click on “Select an action” and choose the desired option.
Choose “Go”.
Confirm.
*** To select multiple client at once, click on the square.
More details on the different possible actions:
Add or remove customers from a group
The query builder allows you to add or remove customers based on criteria you define.
You can find more information in this article.