diff --git a/README.md b/README.md
index 1252516..fbf7d01 100644
--- a/README.md
+++ b/README.md
@@ -60,6 +60,11 @@ This example will open a market position, place a limit buy order, and set a sto
 | **stop_market_sell** |  x  |  x  |     |     |     |
 |   **close_position** |     |     |     |     |     |
 
+### Debug
+
+```
+curl -X POST -H "Content-Type: application/json" -d '{ "account": "first_account", "instrument": "BTC-PERPETUAL", "orders": [{ "t": "debug", "a": 10, "p": 10 }] }' http://localhost:3000/trade
+```
 
 ### Endpoints
 
@@ -67,3 +72,11 @@ This example will open a market position, place a limit buy order, and set a sto
 * `GET /exchanges` to list supported exhanges, useful to find a `ccxt id` 
 * `GET /exchanges/:exchange` to list available instruments (symbols) for a specific exchange
 
+### FAQ
+
+#### Amount unit is in Fiat or Asset?
+It depends on the exchange. Example:
+* deribit: it's fiat on `BTC-PERPETUAL`
+* bitfinex: it's asset on `BTC/USD`
+
+Refere to exchange or ccxt documentation.
\ No newline at end of file
diff --git a/class_config.js b/class_config.js
index b70a0a2..83d8b93 100644
--- a/class_config.js
+++ b/class_config.js
@@ -21,6 +21,9 @@ class Config {
 
 	getAccountParams(account) {
 		let exchange = this.exchanges.find(e => e.account === account)
+		if (!exchange) {
+			throw new Error(`No account named '${account}'`);
+		}
 		let params = exchange.hasOwnProperty('params') ? exchange.params : {}
 		return params
 	}
diff --git a/class_order.js b/class_order.js
index 8f21597..f58b758 100644
--- a/class_order.js
+++ b/class_order.js
@@ -92,7 +92,7 @@ class Order {
 		}
 		console.log("-> Processing", this.order)
 		if (this.order.t == 'debug') {
-			console.log("<- Debug mode, no order placed.")
+			console.log("-x Debug mode, no order placed.")
 			return "executed debug order"
 		} else {
 			switch (this.order.t) {
diff --git a/tests/config.test.js b/tests/config.test.js
index 413a784..65130ec 100644
--- a/tests/config.test.js
+++ b/tests/config.test.js
@@ -14,5 +14,6 @@ test('getAccountParams() returns correct data', () => {
   expect(global.config.getAccountParams("first_account")).toStrictEqual({ "currency": "BTC" });
   expect(global.config.getAccountParams("second_account")).toStrictEqual({ "currency": "ETH" });
   expect(global.config.getAccountParams("third_account")).toStrictEqual({});
+  expect(() => global.config.getAccountParams("unknown_account")).toThrow("No account named 'unknown_account'");
 });