It’s ultimately up to the scholarship provider. If you are applying for a merit-based scholarship (i.e. grade-based) you may be required to provide an official transcript opposed to an unofficial transcript as decisions are made based upon the information, namely your GPA, as stated on your transcript. You can request a copy of your official transcript from your school to send to the scholarship issuer as part of your application. If you’re required to provide an official transcript, don’t wait until the last minute to request one from your school—it can take them up to two weeks to provide you with an official transcript.
While most larger scholarships will not accept an unofficial transcript, there are likely several smaller ones that will. Make sure to read the application carefully to understand the requirements and if you can use an unofficial transcript.