Maybe it is your Python version. I mean, if the SpeechRecognition does not support your Python, you can’t install it.
What is your Python version? You can find it by running py -V.
The PyPI page for the package is here: SpeechRecognition · PyPI. And the GitHub repository (where the source code is stored) is here: Uberi/speech_recognition (github.com).
Looking for the PyPI classifiers, and the settings from the repo, seems like they only support Python >=3.6.