First, do not incur more debt, even with an authorized user. It is considered fraud if you are not the primary user.
After your death, your assets are used to repay your credit card debt. Then, the remaining assets are distributed to your heirs.
That means that your estate is insolvent. In this situation, your heirs may have to repay your credit card debt.
Credit card debt is considered the lowest priority over other obligations, like secured loans backed by collateral.