json decoding error

[deneme2]

Hello my friends,
Wish you al have a restful sunday.
I want to use one json file in python with a following code.

import json
import datetime
import pandas as pd
list=[]
with open("12.json", encoding="UTF-8") as f:
    jsondata = json.load(f)
for matches in jsondata["items"]:
    if "Alternative" in matches["champName"]:
        continue
    list.append([matches["champName"],datetime.datetime.fromtimestamp(matches["dateStart"]),matches["opp1"],matches["opp2"],matches["score"]])
df=pd.DataFrame(list)
df.to_excel("output.xlsx")
print("Saved.")

when I run it, it gives such error.

Error:
Traceback (most recent call last):
  File "c:\Users\monst\Downloads\python_stavka\parcali_results\parcali_results-FilterExcel-dateupdate.py", line 8, in <module>
    jsondata = json.load(f)
  File "C:\Users\monst\AppData\Local\Programs\Python\Python310\lib\json\__init__.py", line 293, in load
    return loads(fp.read(),
  File "C:\Users\monst\AppData\Local\Programs\Python\Python310\lib\json\__init__.py", line 346, in loads
    return _default_decoder.decode(s)
  File "C:\Users\monst\AppData\Local\Programs\Python\Python310\lib\json\decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "C:\Users\monst\AppData\Local\Programs\Python\Python310\lib\json\decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 15 column 1 (char 1472190)

How can I fix that?
Thank you.