Not all tree sap is edible and even if the tree sap from every tree was edible it would not taste all that great coming directly from the tree without going through the process of making it into syrup.
Some tree sap from some trees is actually poisonous and can kill you if you did eat it so you should not eat tree sap unless it comes from a tree that produces edible tree sap.
Maple syrup for example comes from maple trees so the maple tree sap would be edible but any other trees you should avoid eating the tree sap from.
They could potentially make you sick and possibly cause death as well.