Can I use ECC RAM on a consumer Intel board?

No. Intel reserves ECC support for Xeon processors and workstation chipsets like W680. On a consumer Z690 board with a Core i5/i7/i9, the memory controller ignores the ECC bits — you get zero error correction, just slower, more expensive memory. Don’t waste the money; buy standard DDR4 or DDR5 for your Z690 build.