Verifying identity shouldn't you guys cover this for me

Verifying your identity with the IRS can only be done by you, no one else.

Go to this IRS website if you received a Letter 5447C - https://www.irs.gov/individuals/understanding-your-letter-5447c

TurboTax is tax preparation software to assist in completing a do-it-yourself tax return.  It is not a CPA, EA, Tax Attorney or other paid tax professional.

when using TT or any other self-prepared return software, only the taxpayer can verify his/her identity with the iRS.  

Even if you use a paid tax professional only YOU can verify your own identity with the IRS.

It also says you can make them and send and documentation to prove your identity is it too late for me to write them?