atila-diffusion wrote:
I would spend my plugin on 64 bit archicad 13 64 bit, how do I go about it thank you?
The problem is that I have no machine to test on 64 bits.
thank you for your help.

You can still build a 64-bit add-on with a 32-bit platform - just select the x64 platform in your project settings (and switch libraries as required). The API documentation has a guide for this process. However, you really need to a 64-bit platform to test the add-on with.