Yes, it's the resin, NOT the bark, that contains the alkaloids. When you buy the bark, it almost always has the resin removed from it so it’s worthless. The natives remove the resin and sell the bark for other pusposes. So don’t bother buying the bark unless you know the resin wasn’t removed from it. SWIM has NEVER extracted more than 1 dose of 5-MeO-DMT from massive amounts of bark. In most cases nothing is extracted.
Virola theiodoea resin contains mostly 5-MeO-DMT and is what you want. You don’t want Virola calophylla resin because that contains mostly DMT (quite a lot actually).
Chaliponga also contains a lot of 5-MeO-DMT usually, but it contains about 2 times as much DMT. However, if used sublingually, 5-MeO-DMT is many times stronger than DMT so you’ll just get a 5-MeO-DMT trip from it.