Registered users have an option to join an organisation during signup. You can also request membership through the organisation’s page. Please keep in mind that you need to work for the organisation in order to click on the ‘Request Membership’ button and a request will be sent to the organisation’s administrator(s). The requestor can not specify the role (i.e., admin, editor or member). Instead, the person receiving the request assigns the role. If you do not see this option displayed on organisation page, the organisation is a closed group and is not accepting new members.