You can use the npm update command to update all the dependencies in your package.json file to their latest version. Lets see how to use it:

Open your terminal and navigate to the root directory of your project.
Run the following command:

npm update


This will update all the dependencies in your package.json file to their latest version, as defined by the version range specified in the file.

Alternatively, you can also use the npm install command with the --save flag to update a specific dependency to its latest version. 
For example:

npm install --save express


This will update the express dependency to its latest version and save the new version to your package.json file.

Some updates may introduce breaking changes that could break  your code so the best practice is to test your code thoroughly after updating dependencies.