You can remove a gateway with the client app.
Step 1: Navigate to Account tab.
Step 2 — Android: Use the down caret icon in the gateway you want to remove to reveal the actions. Tap the remove icon and confirm the action.
Step 2 — iOS 13 or later: Long press the gateway you want to remove to reveal the actions. Select Remove and confirm the action.
Step 2 — iOS 12: Swipe left the gateway you want to remove to reveal the actions. Select Remove and confirm the action.