# stackoverflow bounty winner answer

import firebase_admin
from firebase_admin import credentials
from firebase_admin import firestore

cred = credentials.Certificate(
        "firestore-cred.json"
    )
firebase_admin.initialize_app(cred)
db = firestore.client()
data = {
    "Email" : email
}

query_email = db.collection(u'Users') \
                .where(u"Email",u"==",data["Email"]) \
                .get()
if query_email:  
    # exists
    ...
else:
    # does not exist
    ...

# Source: https://stackoverflow.com/questions/69120812/how-to-check-if-data-exist-in-firebase-kivymd-python/69183265#69183265
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