Submit a statement of enrollment instead.
My own children attend an Options program while enrolled in PRS and I have had no problem using their statement of enrollment in place of an NOI. You can print or download a copy of your statement of enrollment from your account page.
Keep in mind that individual school districts may have different policies and may not understand what an umbrella school is. The best approach is to ask the district and work out any issues before enrolling. Please contact PRS if you need assistance.