Go to your TreasuryDirect.gov account and log in. That will lead you to your home page where you will find “current holdings.” Click on SavingsBonds as a choice. Then click on I-bonds, when given the choice. That will show you your current holdings and the value (which includes the interest you have been paid).
If you don’t see I-Bonds among your holdings, then you never actually purchased them. (That has happened to manypeople!) It typically takes at least 5 months after purchase for the “value” to increase to account for the interest paid.