Help for recompile my plugin for 64 bit architecture

This message appear in my laptop:
Failed to load ‘Assets/Plugins/QCARWrapper.dll’, expected 64 bit architecture (IMAGE_FILE_MACHINE_AMD64), but was IMAGE_FILE_MACHINE_I386. You must recompile your plugin for 64 bit architecture
I don´t know what to do because i´m new.

In the Unity Editor, select your dll file and then in the Inspector>Platform settings, choose x86 for CPU.

The message should go away now.

Note: If you cannot recompile your dlls for 64 bits, you may want to try Unity 32 bit. Go to Unity download page and download and install Unity 32 bit.