Update README.md

Author: yushulx

.gitignore

@@ -2,3 +2,4 @@ _skbuild
 /build
 dist
 /examples/official/9.x/zxing_zbar/__pycache__/*.pyc
+/examples/official/9.x/jupyter_notebook/.ipynb_checkpoints

examples/official/9.x/nonstandard_1D_barcode/README.md

@@ -5,7 +5,7 @@ This sample demonstrates how to use the [Dynamsoft Barcode Reader SDK](https://w
 Python 3.x
 
 ## Prerequisites
-- Obtain a [Dynamsoft Barcode Reader trial license](ttps://www.dynamsoft.com/customer/license/trialLicense)
+- Obtain a [Dynamsoft Barcode Reader trial license](https://www.dynamsoft.com/customer/license/trialLicense/?product=dbr)
 - Install the Dynamsoft Barcode Reader SDK for Python:
 
     ```bash

examples/official/9.x/zxing_zbar/README.md

@@ -14,7 +14,7 @@ pip install -r requirements.txt
 
 
 ## Usage
-1. Obtain a [Dynamsoft Barcode Reader trial license](ttps://www.dynamsoft.com/customer/license/trialLicense) and update the code with the license key in `app.py`.
+1. Obtain a [Dynamsoft Barcode Reader trial license](https://www.dynamsoft.com/customer/license/trialLicense/?product=dbr) and update the code with the license key in `app.py`.
 
     ```python
     BarcodeReader.init_license('LICENSE-KEY')