Can I buy this program permently

As John Smith already mentioned: no, not possible to get a perpetual license anymore.

You might be able to purchase an older version of CS6 or earlier on eBay, but I would advice against it: too many frauds and illegal versions are being sold on eBay. Ideally you want an unopened box with an unused serial. But even then you might run into activation problems.

Alternatively, look into professional 2d animation software alternatives of which a perpetual license can be purchased  or are open source and free.

OpenToonz (professional level 2d animation software, open source and free!):

Releases · opentoonz/opentoonz_nightlies · GitHub

TVPaint (arguably the best traditional bitmap 2d drawing animation package)

TVPaint Developpement - Web Site

Toonboom Harmony (one of the industry standards):

Toon Boom Harmony | Toon Boom Animation

Moho (excellent for cut-out 2d animation)

Moho® Pro 12 – 2D Animation Software for Professionals

If you have your heart set on Animate CC, your only option is to rent the software. Which isn't as bad as it sounds. But do realize that, once you stop paying the rent, you will lose access to your source animation files, which can only be opened and edited in Animate CC.