To click on the notification icon you need to induce WebDriverWait for the element_to_be_clickable() and you can use either of the following Locator Strategies:
Using CSS_SELECTOR:
WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR, "svg.svg-icon.iconInbox"))).click()
Using XPATH:
WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.XPATH, "//*[local-name()='svg' and @class='svg-icon iconInbox']"))).click()
Note: You have to add the following imports :
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC