Request for offline installer of Photoshop 24.x (2023)

You can try to contact the Adobe customer support and ask they to provide download links to earlier versions. Explain why you need them. But there's no guarantee you'll succeed.

Click on the chat bubble in the lower-right corner:  Photoshop Desktop Help

Type "agent" to chat with a human employee. If the agent isn't able or doesn't want to provide you with download link, hang up and try again. Some users have reported that they have to try several agents before getting one who could help.

If you get the appropriate link and after you've download the installation file it is recommended to save this file to a save place, like external hard drive or usb stick, for a further usage. It isn't guaranteed how long Adobe will make such versions available on demand.