Equivalent of 'curl --cookie-jar' for Python's requests library

Question

I would like to know how to do the equivalent of this:

curl --location --request POST "https://example.com/some/path" ... --cookie-jar "/Path/On/My/Computer"

Using Python's requests library. I tried something like this:

from http.cookiejar import CookieJar
import requests

jar = CookieJar()  # <-- the path should surely be set somehow, but unsure how

session = requests.session()
response = session.post("https://example.com/some/path", cookies=jar, ...)

Although I can't make it work, I keep getting a 403. It works when I try it with Insomnia (https://insomnia.rest/), so the credentials I'm sending are ok, but the cookie jar part is unclear to me. Any help would be very much appreciated, thanks!