From Destiny 2 Wiki
|Description||Tokens earned in the Trials of Osiris. Return them to Saint-14 for rewards. These tokens will expire at the end of the current Trials of Osiris event.|
Trials Tokens can be turned in to Saint-14 in exchange for Trials Engrams. They contain a piece of Trials gear the player has previously collected.
These tokens expire at the end of the current Trials of Osiris event.