Filter relationship in rails json api using many to many

I have these models:

class Account < ApplicationRecord
  has_many :account_members, dependent: :destroy
  has_many :users, through: :account_members
  has_many :projects, dependent: :destroy

end

and

class Project < ApplicationRecord
  belongs_to :account
  has_many :project_members, dependent: :destroy
end

and

class ProjectMember < ApplicationRecord
  belongs_to :project
  belongs_to :account_member
end

and

class AccountMember < ApplicationRecord
  belongs_to :account
  belongs_to :user
  has_many :project_members, dependent: :destroy
end

My account's controller index function

  def index
    @accounts = @current_user.accounts

    render json: @accounts, include: params[:include]
  end

The problem is this action returns the accounts with all projects BUT the user might only be a member of 2 projects. I want it to return only projects that the user has access to through the project_members relationship.

How do you do that?

EDIT 1 I am also using cancancan if that makes a difference.

EDIT 2 This is the account serializer

class AccountSerializer < ActiveModel::Serializer
  attributes :id, :name
  has_many :users
  has_many :account_members
  has_many :invites
  has_many :projects
  has_many :clients
end