I work as a HomeCare Worker and was paid for my Paid Time Off not used. How do I explain that

This is still treated as income.  It was hours accrued and then paid to you as wages for not using them.

It must be reported as income.

It should have been included in your W-2 wages.  If so, then you will just enter your W-2 and there is nothing extra you will need to do.  There is no explanation needed as it is part of your income and not treated any differently than pay you receive for working. 

If it was not included in your W-2 wages, you will need to contact your employer for a corrected W-2 that includes your unused PTO.