How to get version without RTD?

[TheKernelZ]

Hello, thanks for your great work which support my work a lot!
I wonder that if there is a simple way to get version by sphinx-multiversion? Although there is an environment variable named "SPHINX_MULTIVERSION_VERSION", but sphinx-multiversion load config before the variable set.
I have searched a lot of materials where they all get version by RTD'env which cannot fit my work.