A peony label matters most when its leaves are fading and the secateurs are ready. Herbaceous peonies, tree peonies and intersectional hybrids should not all receive an identical cut.
Tree peonies retain a woody framework. Treating those stems as disposable seasonal growth can remove parts you meant to keep. Herbaceous peonies have a different pattern of dieback.
Read the plant and its label together
Find the named variety or ask the nursery to confirm the group. If the label has been lost, examine the stems and seek a reliable identification before making a drastic cut.
Remove clearly fallen debris and assess any damaged material, but do not use autumn tidiness as a reason to erase an unidentified plant's structure. Pruning and disease management may also require different decisions.
Take a photograph before cutting and record the plant's name in a permanent garden list. If several peonies stand together, mark their positions. That small preparation prevents the same uncertainty returning next autumn and helps you follow instructions written for the actual peony in the bed, rather than for a familiar flower name.
The RHS provides separate guidance for herbaceous and intersectional peonies and tree peonies. The former die back seasonally; tree-peony care preserves a woody framework and normally needs little pruning. Identify the group before cutting stems down.
Related reading: Tree Peony vs Herbaceous Peony: Stems, Leaves and Flowers.