BitBucket - Set up SSH key pair for Git
Note: It is required that you download and install Git Bash first. Installation of Git is not covered in this tutorial, you can find "Git - Initial Setup on Windows" on my channel for more details on this topic.
This short video shows how you can create a public/private SSH key pair and register your public key with BitBucket.
Similar approach can be used for GitHub, the only difference is in the last part when you have to register your key using GitHub interface.
This will allow you to clone your repos with this command:
git clone [email protected]:your_username/your_repo.git
Important: Your private key should be available only to you, and your public key is meant to be shared with everyone.