Undefined index Error Opencart 3x

[jurko-s]

I have two sites on Opencart 3.0.3.1
Installed this extension on both sites. That doesn't add tracking numbers to order.
I have this errors in logs:
First site:

2019-08-15 18:12:58 - PHP Notice: Undefined index: tracking_number in /oc3_storage/modification/admin/controller/sale/order.php on line 1544
2019-08-15 18:12:58 - PHP Notice: Undefined index: name in /oc3_storage/modification/admin/controller/sale/order.php on line 1555
2019-08-15 18:12:58 - PHP Notice: Undefined index: web_url in /oc3_storage/modification/admin/controller/sale/order.php on line 1558

Second:
2019-08-15 18:46:19 - PHP Notice: Undefined index: courier_slug in /oc3_storage_b/modification/catalog/controller/api/order.php on line 802
2019-08-15 18:46:19 - PHP Notice: Undefined index: tracking_number in /oc3_storage_b/modification/catalog/controller/api/order.php on line 802

[yangyao]

I have two sites on Opencart 3.0.3.1
Installed this extension on both sites. That doesn't add tracking numbers to order.
I have this errors in logs:
First site:

2019-08-15 18:12:58 - PHP Notice: Undefined index: tracking_number in /oc3_storage/modification/admin/controller/sale/order.php on line 1544
2019-08-15 18:12:58 - PHP Notice: Undefined index: name in /oc3_storage/modification/admin/controller/sale/order.php on line 1555
2019-08-15 18:12:58 - PHP Notice: Undefined index: web_url in /oc3_storage/modification/admin/controller/sale/order.php on line 1558

Second:
2019-08-15 18:46:19 - PHP Notice: Undefined index: courier_slug in /oc3_storage_b/modification/catalog/controller/api/order.php on line 802
2019-08-15 18:46:19 - PHP Notice: Undefined index: tracking_number in /oc3_storage_b/modification/catalog/controller/api/order.php on line 802

We will fix this ASAP.

[Terry-Ye]

Hello, using opencart 3.0.3.1, but failed to find the problem, can you give the usage scenario that triggered the problem?