Dear Sital,
To begin the upgrade process, please ensure that your current device meets the hardware requirements for Windows 10 Professional for Workstations. This edition is optimized for high-performance hardware and includes features such as ReFS file system support and persistent memory.
If you’ve already purchased a valid digital license, you can activate the upgrade by navigating to Settings > Update & Security > Activation, and selecting Change product key. Enter the product key associated with your Workstations edition license. Once validated, Windows will initiate the upgrade automatically.
Alternatively, if your license is linked to your Microsoft account, you may be able to activate it without entering a key by signing in under Settings > Accounts > Your Info.
Please ensure your system is connected to the internet during this process, and that all pending Windows updates are installed beforehand to avoid compatibility issues.
If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.
Best regards,
Harry Phan