Once you've invited someone to join your company account, they'll receive an email containing a link. Upon clicking the link they'll have the opportunity to choose their own password for securely accessing their own personal profile.
It's important to note the the invite link is unique to each person. Multiple people can't join your company using the same link. They each need to use the unique invite link generated for them.
If you're having trouble with this process, here are a few helpful tips:
Make sure the invitation email isn't hiding in the person's spam/junk folder. Emails sent from systems are sometimes flagged as spam.
If the person still isn't getting the invitation email, try emailing them the invite link from your own email account.
If you're trying to use the link on the person's behalf, note that you must be logged out of the system when you do this. If the system recognizes that you're already logged in, it'll just ignore the invite process.