Select and save multiple Checkboxes with simple for - ruby-on-rails

Question

I'm trying to implement a multiple select and save with simple form and nested forms.
My view shows all the branches with name and description in a card format (Bootstrap). Next to te name I would like to have a checkbox. I would like to save only the selected ones
= simple_form_for(#my_branch, html: { class: 'form-horizontal' }) do |f|
= f.error_notification
= f.input :user_id, input_html: { value: current_user.id}, as: :hidden
- #branches.each do |branch|
= f.simple_fields_for :my_branch_items do |b|
.col-md-4
.card{:style => "width: 18rem;"}
.card-header
= branch.name
= b.input :branch_id, input_html: { value: branch.id }, as: :radio_buttons
%ul.list-group.list-group-flush
= branch.description
.form-group
= f.submit 'Save', class: 'btn btn-primary'
Here are the associations
class Branch < ApplicationRecord
has_many :my_branch_items
end
class MyBranch < ApplicationRecord
belongs_to :user
has_many :my_branch_items
accepts_nested_attributes_for :my_branch_items, allow_destroy: true, reject_if: proc { |att| att['name'].blank? }
end
class MyBranchItem < ApplicationRecord
belongs_to :my_branch
belongs_to :branch
end
And the Controller
class MyBranchesController < BaseController
before_action :set_my_branch, only: [:show]
def new
#branches = Branch.all
#my_branch = MyBranch.new
end
def create
#my_branch = Quiz.new(my_branch_params)
if #my_branch.save
redirect_to my_branch_path(#my_branch), notice: 'Thanks for taking the Branch Quiz'
else
render :new
end
end
def show
end
private
def set_my_branch
#my_branch = MyBranch.find(params[:id])
end
def my_branch_params
params.require(:my_branch).permit(:name, :note, :user_id, my_branch_items_attributes: MyBranchItem.attribute_names.map(&:to_sym).push(:_destroy))
end
end

Answer 1

Fixed!
Form
= simple_form_for(#my_branch, html: { class: 'form-horizontal' }) do |f|
= f.error_notification
= f.input :user_id, input_html: { value: current_user.id}, as: :hidden
- #branches.each do |branch|
= f.simple_fields_for :my_branch_items do |b|
.col-md-4
.card{:style => "width: 18rem;"}
.card-header
= branch.name
= b.input_field :branch_id, checked_value: branch.id, as: :boolean, boolean_style: :inline, include_hidden: false
%ul.list-group.list-group-flush
= branch.description
.form-group
= f.submit 'Save', class: 'btn btn-primary'
Model was using a validation for blanks field that did not exist in the table.
class MyBranch < ApplicationRecord
belongs_to :user
has_many :my_branch_items, dependent: :destroy
accepts_nested_attributes_for :my_branch_items, allow_destroy: true, reject_if: proc { |att| att['branch_id'].blank? }
end