Yes.
According to the official MathJax documentation, version 2.7:
While MathJax includes nearly all of the Plain TeX math macros, and
many of the LaTeX macros and environments, not everything is
implemented in the core TeX input processor. Some less-used commands
are defined in extensions to the TeX processor.
MathJax will load some extensions automatically when you first use the
commands they implement (for example, the \def and \newcommand macros
are implemented in the newcommand.js extension, but MathJax loads this
extension itself when you use those macros). Not all extensions are
set up to load automatically, however, so you may need to request some
extensions explicitly yourself.
To enable any of the TeX extensions, simply add the appropriate string
(e.g., "AMSmath.js") to the extensions array in the TeX block of your
configuration. If you use one of the combined configuration files,
like TeX-AMS_CHTML, this will already include several of the
extensions automatically, but you can include others using a mathjax
configuration script prior to loading MathJax. For example:
<script type="text/x-mathjax-config">
MathJax.Hub.Config({ TeX: { extensions: ["autobold.js"] }});
</script>
<script type="text/javascript"
src="https://example.com/mathjax/MathJax.js?config=TeX-AMS_CHTML">
</script>
will load the autobold TeX extension in addition to those already
included in the TeX AMS_CHTML configuration file.
You can also load these extensions from within a math expression using the non-standard \require{extension} macro. For example:
\(\require{color}\)
would load the color extension into the page. This way you you can
load extensions into pages that didn’t load them in their
configurations (and prevents you from having to load all the
extensions into all pages even if they aren’t used).
Source: https://docs.mathjax.org/en/v2.7-latest/tex.html#tex-and-latex-extensions
If you want to work with version 3, here is the documentation:
https://docs.mathjax.org/en/v3.0-latest/input/tex/extensions.html
If you want the latest version:
https://docs.mathjax.org/en/latest/input/tex/extensions.html