Box chars characters (Missing character: There is no ┬ in font)

I am using Sphinx to build a project that use listings and some box characters. I have these errors:

Missing character: There is no ─ in font [lmmono9-regular]:!
Missing character: There is no ┬ in font [lmmono9-regular]:!
Missing character: There is no ─ in font [lmmono9-regular]:!
Missing character: There is no ┦ in font [lmmono9-regular]:!
Missing character: There is no │ in font [lmmono9-regular]:!
Missing character: There is no │ in font [lmmono9-regular]:!

For example I have this in my RST files:

.. code-block:: text

    ┌─┬─┬─┬─┬─┬─┬─┬─┐
    │0│1│0│1│0│0│1│1│ = 0b1010011 = 83
    └─┴─┴─┴─┴─┴─┴─┴─┘

Which is transpiled into:

begin{sphinxVerbatim}[commandchars={}]
┌─┬─┬─┬─┬─┬─┬─┬─┐
│0│1│0│1│0│0│1│1│ = 0b1010011 = 83
└─┴─┴─┴─┴─┴─┴─┴─┘
end{sphinxVerbatim}

What can I change to support normal unicode chars?

I build the tex file with:

latexmk -xelatex -pdf main.tex

usepackage{xeCJK}
usepackage{lstfiracode}

setCJKmainfont{ipaexm.ttf}
setmonofont{Fira Code}