What is the proper amount to enter when filing charitable contribution

Hello, i have a question about how to fill in this information within Turbotax, i assume this is a common question, but i am not sure exactly. Here is my scenario

I am taking standard deduction married which means i have a $600 credit limit

I gave out $1000 to charities in 2021

I understand unused charitable contributions can be carried over to other years. 

My question then is what is the proper way to file this within turbotax? Do i

a) Write $1000 this year, then put the carryover $400 when i file in 2022?

b) Write $600 this year, then put the carryover $400 when i file in 2022?

TIA