You can't change that amount. The spouse or common-law partner amount is calculated based on your spouse/partner's net income. However, you can choose not to claim the amount altogether.
If you're preparing your spouse/partner's return together at the same time as your own, TurboTax automatically pulls your spouse's net income amount from their return to calculate the credit.
If you're not preparing your returns together, you need to enter your spouse/partner's net income amount in your return. It's important to enter this amount accurately because your eligibility for many credits and benefits are based on your family income.
If your spouse/partner is a non-resident of Canada, you may still be eligible for the spouse or common-law partner amount if you are supporting them. If you immigrated or emigrated during the tax year, the CRA recommends that you contact them to understand if you're eligible for the amount.
Finally, if you don't want to claim the spouse or common-law partner amount on your tax return, see our FAQ What do I do if I don't know my spouse's income? for instructions on how to remove it from your return.