Opened HSA acct. in error

I opened an HSA account in 2020. My employer deducted $600.00 total for the year from my paycheck and I contributed $1000.00 of my own money as a catch-up. I spoke to HR and they directed me to the HSA company. They gave me forms to fill out to attain the funds and close the account. But I have already received my W-2 which shows the amount in Box 12 of 600.00. 

Am I going to need a corrected W-2 or can I send the original in with an explanation.