What is the annual tuition fee of Finnish public middle schools? What are the requirements for going to high school in Finland?

First of all, all local high schools in Finland are tuition-free, except for some international schools, but because Finland is not an immigrant country, it is not as easy to attend high schools as going to the United States and Australia, nor can it be done through intermediaries. What I know now is that parents can open stores here or their immediate family members can only ask for it if they marry Finnish natives. If English skills are basic, Finnish depends on the requirements of the school.