Manifest Charm of Lamannia, the Twilight Forest
Charm
When you use a spell slot to cast a spell that conjures or summons a Beast, an Elemental, or a Fey (including Conjure Animals, Conjure Elemental, Conjure Fey, Conjure Minor Elementals, Conjure Woodland Beings, Find Steed, Summon Beast, Summon Elemental, or Summon Fey), you can expend the Charm (no action required) to treat the spell as if it were cast using a spell slot 1 level above the slot expended.
Source: Eberron: Forge of the Artificer