In order to be eligible to apply, you need to earn at least €760 per month as an individual (€9,120 per year). As a married couple, your combined passive income should be at least €1,140 per month (€13,680 per year), so an additional €380 per month for your spouse).
For every dependent child being applied for, the minimum monthly passive income requirement increases by €228 (€2,736 per year) which is around 30% of the minimum national wage in Portugal.