You can invite members to your Community in the following steps:
1. Click on the Commerce tab on the left side bar.
2. Click on Community.
3. Hover to the Community you want to add members to.
4. Click on the three dots to the side of the community
5. Select the Invite members to community.
6. You can also invite by link or by sending an email.
7. Watch the video below for more information.