I dont know my ex's net income so what should i do to continue
If you separated from your spouse in the tax year and you don’t know your ex-spouse’s or ex-common law partner’s income amount and other tax information for the year, you should try to estimate these amounts based on what you know.
For example, if you have a separation agreement, you might be able to estimate your ex-spouse’s income from there or from a previous year's tax return, if their situation has remained the same.
Keep in mind, if you enter amounts that are too low, you might end up claiming benefits that you’re either not entitled to or amounts that are more than what you’re entitled to. This might result in the Canada Revenue Agency (CRA) clawing back these benefits and you having to pay interest charges and penalties.