Can I change the state tax refund

Why do you  think it's wrong?   Go back and double check your W2 entries boxes 15-20.

.......or do you mean the $$ amount you received from last year's (2020) state refund?

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That entry can be corrected on the Wages&Income page, 

in the "Other Common Income" section, is one called "Refunds Received for State/Local Tax Returns".

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Cautions: If slightly different from what you received in yoru bank account, or by check...etc..the number TTX transferred may be correct.  The correct refund number used is a number before any deductions for any "use Tax" you paid, or before any check-off deductions for any state charities you directed some of your refund to.

Alos, as you go thru that section, even if the number is wrong, it won't be used as Federal income this year, if you used the Std Deduction on last year's Federal taxes (i.e. 2020 taxes)