You missed the window to lock in the older interest rate (7.12% APY) for six months, but it is widely expected that the May rate change will increase the rate even higher.
You can still purchase I-Bonds, with the understanding that the May rate will be adjusted again in 6 months (it could go down if inflation goes down) and you won't be able to pull your funds for a minimum of one year.
It's a great option for inflation protection if you can let that money sit for awhile. https://www.treasurydirect.gov/indiv/research/indepth/ibonds...