If your T2201 has not been submitted and approved by CRA, then you will not be able to successfully NetFile your tax return and must mail it in along with the completed and signed form.
If you have already submitted the T2201 - Disabiity Tax Credit form and are unsure of the state of approval on it, you can sign in online to your CRA My Account or call CRA to check the status.
Here's some more information on the T2201 approval process: https://www.canada.ca/en/revenue-agency/services/tax/individuals/segments/tax-credits-deductions-persons-disabilities/disability-tax-credit/after-you-send-form-t2201-step-step-process.html