Github organisations have disabled the usage of deploy keys by default, as explained [here](https://docs.github.com/en/enterprise-cloud@latest/organizations/managing-organization-settings/restricting-deploy-keys-in-your-organization).

If you face this error, you need to:

1.  In the upper-right corner of GitHub, select your profile photo, then click  **Your organizations**.
2.  Next to the organization, click  **Settings**.
3.  In the "Access" section of the sidebar, click  **Member privileges**.
4.  Under "Deploy keys", review the information about changing the setting, click  **Enabled**  or  **Disabled**.
5.  Click  **Save**.