For Premium Version - License Activation
To activate license and install this premium TYPO3 product, please refer to this documentation: LicenseFor Free Version
Via Composer using Command Linens_helpdesk and import the extension from the repository.
Step 4. Get it from typo3.org: You can always get the current version from https://extensions.typo3.org/extension/ns_helpdesk/ by downloading either the t3x or zip version. Upload the file afterwards in the Extension Manager.