Been exploring AGOL and the ability to share outside the organisational account. I've looked at a few posts/blogs on geonet and they have lead me to creating a group and then inviting people into it as shown below. I am the administrator for our account and the creator of the group.
As I understand it I simply need to untick the box circled in red and then type peoples names. But the check box is greyed out and I cannot invite anyone.
What, if anything, am I doing wrong?