Rails 7.0.4 Error when in run some code of ruby on rails

Question

no implicit conversion of Hash into String

class PostsController < ApplicationController @posts = Post.all

  respond_to do |format|
    format.html
    format.csv { send_data @posts.to_csv }
    format.xls { send_data @all.to_csv(col_sep: "\t")}
  end

class Post < ApplicationRecord

def self.to_csv(options = {}) attributes_post = %w(title, description)

CSV.generate(options) do |csv|
  csv << column_names
  all.each do |post|
    csv << post.attributes.values_at(*attributes_post)
  end
end

end