Cast doesn't work as expected when concatenating strings

I am trying to achieve the simplest task - creating the FISCAL_YEAR column as shown below (column YEAR is given):

+------+-------------+
| YEAR | FISCAL_YEAR |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+

I keep getting the error: can only concatenate str (not "int") to str


These are the steps I've tried so far, without success:

1. df['fiscal_year'] = str(df['year']) + "-" + str(df['year']+1)

2. df['fiscal_year'] = df['year'].astype(str) + "-" + (df['year']+1).astype(str)

df['year_str'] = pd.Series(df['year'], dtype=pd.StringDtype())

And also:

df['year_str'] = df['year'].astype(str)

And then:

df['year_str'].str.cat(df['year_str'].astype(int) + 1, sep='-')

None of these options work. Is there is anything else I'm missing?

** I am on Windows 10 and Python version 3.9.7

A failproof way could be:

df['FISCAL_YEAR'] = (df['YEAR'].astype(str)
                     +'-'+
                     df['YEAR'].astype(int).add(1).astype(str)
                    )

Output:

   YEAR FISCAL_YEAR
0  2022   2022-2023
1  2022   2022-2023
2  2022   2022-2023
3  2022   2022-2023