···147147```
148148jlpm add patch-package
149149```
150150+151151+## Additional configurations
152152+153153+You will need to request the `jupyterlab-blockly` package as a dependency of your extension, in order to ensure it is installed and available to provide the token `IBlocklyRegistry`. To do this, you need to add the following line to your `setup.py` file.
154154+155155+```python
156156+// setup.py : 57
157157+158158+setup_args = dict(
159159+ ...
160160+ install_requires=['jupyterlab-blockly>=0.1.1,<0.2']
161161+ ...
162162+)
163163+```
164164+165165+Moreover, as we are working with deduplication of dependencies and the extension you are creating requires a service identified by a token from `jupyterlab-blockly`, you need to add the following configuration to your `package.json` file.
166166+167167+```
168168+// package.json : 88-101
169169+170170+"jupyterlab": {
171171+ "sharedPackages": {
172172+ "jupyterlab-blockly": {
173173+ "bundled": false,
174174+ "singleton": true
175175+ },
176176+ "blockly": {
177177+ "bundled": false,
178178+ "singleton": true
179179+ }
180180+ }
181181+ }
182182+```
183183+This ensures your extension will get the exact same token the provider is using to identify the service and exclude it from its bundle as the provider will give a copy of the token. You can read more about deduplication of dependencies [here](https://jupyterlab.readthedocs.io/en/stable/extension/extension_dev.html#deduplication-of-dependencies), in the official *Extension Developer Guide for JupyterLab*.