You can't.  Buy them at a bank, or online through TreasuryDirect.  

You should check with your tax pro, but I believe if you put them in parents name, they can use them for education tax free

Good morning,

Do you have a referral for banks that still sell Savings Bonds?

Thank you!

@SensibleandHourly 

You can google this:

buy savings bonds

You can purchase a paper I bond using form 8888 the Allocation of Refund in addition to obtaining them electronically.