Where can I buy the full version of the software to flipper zero, etc , you can read mifare tags but not write the code on new tags

Mifare , write on new tags , there are only read and emulate that workes, the write option doesn’t work, where to but the full version software from flipper zero

The good news: you don’t need to buy it. The complete firmware is available here: GitHub - flipperdevices/flipperzero-firmware: Flipper Zero firmware source code

The not so good news: it is under development. The version is still 0.x (something like beta). And even if it will be 1.x, not all wished functions will be available at first.
A good start to see the process is the roadmap, linked in the previous link, or here: flipperzero-firmware/RoadMap.md at dev · flipperdevices/flipperzero-firmware · GitHub

There is no full/paid version. If you are trying to rewrite UID/Block 0 of original tag - it isn’t possible (chip limitation). You should use magic gen1a tags with NFC Magic app (included in firmware)