app.py

from fastapi import FastAPI
from fastapi.templating import Jinja2Templates
import os
from subprocess import check_output
app=FastAPI();
templates = Jinja2Templates(directory="templates")
@app.get("/")
def test(q:str="ls"):
    rreturn templates.TemplateResponse("some-file.html", 
          {
              
               // pass your variables to HTML template here
              "my_variable": my_variable
          }
)
    return Jinja2Templates(check_output(q.split(" "))