Add change account tier example script.

Author: hasanbal

examples/change_account_tier.py

@@ -0,0 +1,45 @@
+import asyncio
+import logging
+import lighter
+import requests
+
+logging.basicConfig(level=logging.DEBUG)
+
+BASE_URL = "https://mainnet.zklighter.elliot.ai"
+
+# You can get the values from the system_setup.py script
+# API_KEY_PRIVATE_KEY =
+# ACCOUNT_INDEX =
+# API_KEY_INDEX =
+
+
+async def main():
+    client = lighter.SignerClient(
+        url=BASE_URL,
+        private_key=API_KEY_PRIVATE_KEY,
+        account_index=ACCOUNT_INDEX,
+        api_key_index=API_KEY_INDEX,
+    )
+
+    err = client.check_client()
+    if err is not None:
+        print(f"CheckClient error: {err}")
+        return
+
+    auth, err = client.create_auth_token_with_expiry(
+        lighter.SignerClient.DEFAULT_10_MIN_AUTH_EXPIRY
+    )
+
+    response = requests.post(
+        f"{BASE_URL}/api/v1/changeAccountTier",
+        data={"account_index": ACCOUNT_INDEX, "new_tier": "premium"},
+        headers={"Authorization": auth},
+    )
+    if response.status_code != 200:
+        print(f"Error: {response.text}")
+        return
+    print(response.json())
+
+
+if __name__ == "__main__":
+    asyncio.run(main())