An action with this trait requires a degree of mental concentration and discipline.
Spellshape
Actions with the spellshape trait tweak the properties of your spells. You must use a spellshape action directly before casting the spell you want to alter. If you use any action (including free actions and reactions) other than casting a spell directly after, you waste the benefits of the spellshape action. Any additional effects added by a spellshape action are part of the spell's effect, not of the spellshape action itself.
Source: Player Core pg. 121
When you pull forth vitality or void energy, you also create a smaller pocket of that energy. If the next action you use is to cast a 2-action harm or heal to heal or damage a single creature, choose one additional creature in range. Target that creature with a 1-action version of the same spell. This spell is the same rank as the 2-action harm or heal you cast and doesn’t cost another spell slot.