Sorry, i386 has been adandoned for good, there is not going to be a 32bit version of Volumio 3.
The small number of 32bit devices left does not justify the maintenance work we would have.
You can install Volumio 2 for x86 if you wish, but it is unsupported and may stop working at one point (certificate issues etc.).
You will find the version and download information you need when you click on the blue banner at the top of the community forum pages