No, you can't use the Help to Buy equity loan scheme with a Gen H mortgage, where you would be looking to add income or deposit boosters to your application.
This is because the Help to Buy rules state that you must not own any other residential property, or have your name attached to the deeds of another residential property, in the UK or abroad. The home purchase through an equity loan must be the only home you will own.
Whilst your income or deposit booster may not own a property now, they may wish to do so in the future. This does mean in relation to the Help to Buy scheme, income and deposit boosters would be ineligible.
You can read more about Help to Buy eligibility here.