Cache or Reuse Mongodb connection in AWS lambda using Python

I'm building a serverless application using Python and Mongodb. In documentation I found that I need to write db connection outside handler function. I have used Mangum python package as adapter to handle API gateway.

from fastapi import FastAPI
from mangum import Mangum

def get_application() -> FastAPI:
    application= FastAPI()
    #db is creating instance of AsyncioMotorClient #coded in another file
    db.client = AsyncIOMotorClient(str(MONGODB_URL),
                                   maxPoolSize=MAX_CONNECTIONS_COUNT,
                                   minPoolSize=MIN_CONNECTIONS_COUNT, 
                                   waitQueueMultiple = MAX_DB_THREADS_WAIT_COUNT,
                                   waitQueueTimeoutMS = MAX_DB_THREAD_QUEUE_TIMEOUT_COUNT )
    return application

app =get_application()

@app.get("/")
def read_root():
   
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: str = None):
    return {"item_id": item_id, "q": q}

handler = Mangum(app)

For every API request, new connection is created. How to cache db so that new request uses old connection. Every time new request is created so that lambda compute time is increased dramatically after db hits max connection limit.