Switching GCC version to use on macbook M1

I received this error when I tried to compile by gcc 11.x and run some code on my Macbook Pro M1

E ImportError: dlopen(/Users/giangpham/VSCode/rpxdock/rpxdock/bvh/bvh.cpython-37m-darwin.so, 0x0006): tried: ‘/Users/giangpham/VSCode/rpxdock/rpxdock/bvh/bvh.cpython-37m-darwin.so’ (mach-o file, but is an incompatible architecture (have ‘arm64’, need ‘x86_64’))

I tried to install another homebrew for x86_64 architecture and install the old gcc ver 9 (which is the version recorded to have worked with the code before) following this article

I have done axbrew info gcc and it would still give out information of the 11.x gcc (axbrew info gcc@9 works and gives me info of the package. But I tried switch`` as the article suggested and it saids unknown command```). How do I switch gcc to use the older version I just installed?

Thank you!