If you want to create a Public Link directly using the Web-client, here's a short guide.
What you will need to do:
1. Open your browser and login with your credentials.
2. Navigate to the folder/file you want to create a public link for.
3. Right-click the file, and the options menu will be shown, where you can select "Create public link".
4. A pop-up will be shown, where you can add a personal message, enable password protection and add an expiry date - press save when you are done.
5. The URL-link will now be shown and ready to be sent.