I solved it by myself:
u16 text[] = { '2', L'Щ', L'ä', L'Ø', '\0' };
SDL_Surface *info = TTF_RenderUNICODE_Blended(font, text, fontColor);
Loop:
SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, info);
SDL_Rect src = { 0, 0, info->w, info->h };
SDL_Rect dst = { 0, 0, info->w, info->h };
SDL_RenderCopy(renderer, texture, &src, &dst);
SDL_DestroyTexture(texture);