Inviting team members can be done in several ways:
During the onboarding steps on Getting started page.
"Invite a team member" button in the main header.
Users page.
Slack home tab.
Method 1. Continue through Getting started page until you reach the "Invite other users" step.
Enter email addresses then click next.
Method 2. Click on "Invite a team member" button in the header.
In the following window, choose to invite a single user or invite in bulk.
When inviting a single user, enter their email address, select their permission level and click "Invite".
If inviting users in bulk, type users' emails by separating them with coma, select their permission level and click "Invite". You can also upload a CSV file (limit 100 records per file).
Please note, when inviting new users, their email addresses must be from the same domain as yours, i.e users with personal emails or emails from other domains won't be able to join your account.
Method 3. Navigate to Users page by clicking on your profile image and press "Users" (visible to Admins only).
On this page you can manage your active, inactive and guest users. To add new users click on "Invite users" button. The rest of the steps are same as above.
Method 4. Open the Deskfound home tab in your Slack window.
Scroll down to bottom and select "Invite Team Members". On the following window, enter comma separated list of emails and click "Invite".