There are 2 ways you can follow to invite members to your organisation.
Managemement Tools
Go to your organisation page and click on ‘Management Tools’.
Choose ‘Invite Members’ and this will give you a link to copy and share with your members.
Invite a Member Button
Go to ‘Members’ section from your organisation page.
Click ‘Invite a member’ button and this will also give you a link to copy and share with your members.
When your members use this link, they are automatically registered to the platform as your organisation’s members. Then you can decide if you want to make them an admin or delete their membership.