You have to switch to the new Free subscription that has the browse termbase option.
NOTE: the new Free subscription has 1 termbase for terminology management instead of 5. If you have more than 1 termbase in your Language Cloud account you will lose them, so make sure to save them before switching the subscription. It should look like this so you can see the browse termbase function on the Free subscription.
Browse the termbase by clicking on the termbase name