Yes.
Either push it upright if the roots will permit. You may need to tie it somehow while it adjusts to the change. Tie to the side of the pot/ push a stick into the right side and tie trunk to it/ other????
OR. Repot so the trunk is upright.
This is also not difficult. Slip the whole rootball out of the pot. Add some potting mix to the left side. Place the tree back into the pot so that the trunk is vertical. scrape off the mound of soil on left side. Job done.