Received a FTB 4734D from state of California. What should I do next?

Form FTB 4734D usually requests copies of:

The taxpayer's Social Security card(s);
W-2 and 1099-R forms; and
Paycheck stubs.

Call the number on the notice for any questions.

Your tax return was selected for review as a security measure to protect against tax-related identity theft.

We need more information from you before we can approve your tax refund.

Gather the required items and complete the Request for Tax Information and Documents form (FTB 4734D) and send it to us:

• Fax: 916.843.6036
• Mail: Filing Compliance Bureau MS F-151
  Franchise Tax Board
  PO Box 1468
  Sacramento, CA 95812-1468

If you do not send the required supporting documentation within 30 days of the notice date, we may disallow (not approve) your claim for refund. Allow 8 weeks for us to review and respond to the documents you send. If you have questions about this notice, call 916.845.7088.

https://www.ftb.ca.gov/Bills_and_Notices/individuals-common-notices.shtml

After speaking with Turbo Tax, I decided to verify the request before sending all this sensitive information. After negotiating the automated phone system, I spoke with a person that verified my name and SS#. Telling him I had no check stubs (destroyed the hard copies), he said that the W2 was not considered a legal document in CA. That's why they ask for the check stubs in addition to W2, 1099, etc. He said a note telling why the stubs are not available is fine. He asked if I would be willing to hold while he checked on my withholding update. Hm, ok, especially since an update to CA would mean I could ignore the letter. When he came back on in about 5 minutes he said I could ignore the letter: they had updated withholding information. I took his first name and ID number just in case and thanked him very much. Now I can put all those nasty documents away and go back to screwing around. Big sigh of relief! 

I mailed the Documents March 15, 2020 should I fax my documents, incase they never received mail?  I activated my intuit card IRS is still being processed.

Thank you for sharing a detailed reply. I got notice today and I called up number on FTB site for Compliance Bureau to verify. Lady on phone did exactly the same, put me on hold and verify things and then asked me 5-8 questions on 2020 tax form. She was satisfied with all answers and said I can ignore the notice and don;t need to do anything. She only shared her name not id number. I was so relieved.  Thank you again!

Same experience here. I called the FTB (was no wait time at 7am), a rep looked up my info, verified some things over the phone, and then cleared the 4734D document request. Much simpler than mailing/faxing in a lot of paperwork. Thanks to everyone for the tips!

Today, this reply from @SweetieJean also worked for me. It's the same phone number, but the link to the FTB webpage is no longer found. I verified the FTB info here: https://www.ftb.ca.gov/help/scams/identity-theft.html in the section titled Report identity theft. After calling+1 (916) 845-7088 a few minutes past 7 a.m. Pacific Time, I pressed 2 in the phone tree, and then listened to hold music for about 20 minutes. After being connected with an FTB rep, they gave me their name, and then my experience was similar to kurt's, anky's and user1430594's. Relived and glad that no faxing or snail mailing will need to be done.