I changed plans. How can I prove that I have purchased the images of the old plan?
Your licence history is not dependant with your plan. If you do not see your history, there is a different problem, like changing the Adobe ID, or going from an individual plan to a Teams or Enterprise plan. in the latter case, the licence history is still attached to you ID, but you need to sign out and sign in again and choosing the individual account.
OK, that's right. The 750 photo plan had [Moderator deleted private information. Please do not post private information like e-mails and phone numbers] as its account; the current one [Moderator deleted private information. Please do not post private information like e-mails and phone numbers]. But how can we access the library of the old plan to prove to Copytrack that we have regularly purchased images from Adobe?
You need to sign in to the old ID to look at the licence history.