You can install aiida-tbmodels with

python -m pip install aiida-tbmodels

where python is the interpreter for which you installed AiiDA.

To run TBmodels calculations, you will also have to set up the tbmodels CLI as an AiiDA code. After installing TBmodels, you can run which tbmodels to find the full path of the executable. Make sure to put unset PYTHONPATH into the prepend text of the code, since the PYTHONPATH set by AiiDA might interfere with your TBmodels installation.