2024 Traditional IRA contribution in 2025

Hello,

I dont know much about the conventional IRA contribution for tax purpose. And I may be confusing my self.

I was filling out 2024 taxes in turbotax and at the end it told me that if I contribute $7000 in conventional IRA then I will be able to save around $1500 in my federal and OH state taxes. So I added $7000 for IRA contribution and filled the taxes. and Both federal and state are accepted.

Now I went on my Robinhood account on the same night to add $7000 in traditional IRA at that time it allowed my to contribute only $6300.

Then after I did amendment in turbotax to send due taxes for $700. It give the print out to send to IRS and the OH. 

But Do I need to prove anything to IRS that I invested $6300 in conventional IRA with Robinhood? 

Also I read few times about 1099-R. Do I need to have it and how do I get it?

Please help me to het the answers for those two questions.