Not in Adventurer’s League.
The Adventurer’s League is the official play venue for Dungeons and Dragons 5e run by Wizards of the Coast. In Adventurer’s League play, you’re limited to using the rules in the Player’s Handbook plus one other book, aside from equipment and a few specific rules mentioned in the AL player guide. That book could be Xanathar’s Guide to Everything or Tasha’s Cauldron of Everything, but you can’t use both at the same time, like using a subclass from one book and spells from another.
It’s possible that as time goes on and more books are released, this rule might be loosened or removed, but for now, it remains in force.