Noita Orb Atlas
This website displays the locations of all the orbs in Noita, including locations to spawn orb 11 from a great chest.
The Great Chest orb can be obtained by getting a great chest to spawn at exactly the given coordinates. Methods to spawn a great chests include casting end of everything, killing leviathan, or rolling greed dice. This orb has never been obtained in a random-seed unmodded run. The portal room search checks locations that are easy to align for the portal/EoE method (~0.05% chance per seed). There is also a command line version of the great chest searcher that is much faster.