A few things can explain why you don't see Invite or full team management:
You need a paid plan
Inviting team members requires an active paid subscription. If your team doesn't have one, you'll see a message like "Subscribe to a paid plan to unlock team collaboration" and a link to view plans. The Invite button may be disabled with a tooltip.
You're a Member, not an Admin
Only team Admins can invite people, change the team name, and remove or disable members. If you're a Member, you'll see the team name and the list of members but not the Invite button or action buttons. Ask your team Admin to change your role if you need those permissions.
You were removed or disabled
If you were removed from the team or disabled, you'll no longer have access to that team's boards or the Team Members section for that team. You'd need a new invite from an Admin to rejoin.