Canadian scholarships for international students applying to high school in the province are somewhat limited. Because the provinces all have a publicly funded secondary school system, there are no scholarships or bursaries provided for students attending the public school system.
Some private high schools have financial assistance programs for students and families--including international students--who demonstrate financial need. The availability of these programs and the amount of financial aid they provide will vary from school to school. You should contact the school you hope to attend for more information if you think you would qualify for this aid.
You should also know that many high schools in the province offer scholarships to graduating students. So while scholarship money may not be available to international students at the beginning of their high school study in the province, it may be available at the end. The government of Canada maintains a database of scholarships for non-Canadians, which is searchable by your country of origin. These, however, are mostly for post-secondary study. Loan assistance may be available to international students through the International Education Finance Corporation (IEFC).