RailsにGoogle Mapを表示させたい

前提・実現したいこと

RailsにGoogle Mapを表示させたいです。

Google Developer ConsoleからAPIキーを取得し、Viewに以下を記載しましたがエラーになりました。

<%= content_tag(:iframe, 'map', src:'https://www.google.com/maps/embed/v1/place?key=APIキー&q=' + comment.address, width: 400, height: 200, frameborder: 0) %>

仮にcomment.addressがtokyoだった場合、

<%= content_tag(:iframe, 'map', src:'https://www.google.com/maps/embed/v1/place?key=APIキー&q=tokyo', width: 400, height: 200, frameborder: 0) %>

とすると表示されるので、リンクには問題がないかと思います。

commentコントローラは以下の通りです。

  def create
    comment = Comment.new(comment_params)
    comment.user_id = @current_user.id
    if comment.save
      flash[:notice] = 'Comment was posted'
      redirect_to posts_index_path(comment.post_id)
    else
      redirect_to posts_index_path(comment.post_id), flash: {
        comment: comment,
        error_messages: comment.errors.full_messages
      }
    end
  end

Rails consoleではaddressが表示されているので、保存も問題がないかと思います。

irb(main):001:0> comment = Comment.all
#<Comment id: 3, post_id: 1, name: "eee", comment: "fff", user_id: 1, created_at: "2020-09-19 14:57:59", updated_at: "2020-09-19 14:57:59", address: "tokyo">]>

しかし実際に表示させようとすると以下のエラーが出てきてしまいます。

すみませんが解決のためアドバイスを頂けないでしょうか。
よろしくお願いします。

追記：comment.html.erb

Google Mapは表示できていませんが、comment.nameやcomment.created_atなど他のcommentモデルのカラム情報は表示できています。

  <p><%= simple_format(comment.comment) %></p>
  <br/>

    <%= content_tag(:iframe, 'map', src:'https://www.google.com/maps/embed/v1/place?key=APIキー&q=' + comment.address, width: 400, height: 200, frameborder: 0) %>

  <br/>
  <div class="p-comment__bottomLine">
    <span><%= comment.name %></span>
    <br/><br/>
    <span><%= comment.created_at %></span>
    <br/><br/>
    <% if comment.user_id == @current_user.id %>
      <%= link_to '削除', comment, method: :delete, data: { confirm: '削除してもいいですか?' }, class: 'btn btn-primary' %>
    <% end %>
  </div>

追記：エラーログとrails consoleでの値の入力確認

Started GET "/posts/1" for IPアドレス at 2020-09-20 04:14:24 +0000
Cannot render console from IPアドレス! Allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255
Processing by PostsController#show as HTML
  Parameters: {"id"=>"1"}
  [1m[36mUser Load (1.1ms)[0m  [1m[34m
	SELECT
		`users`. *
	FROM
		`users`
	WHERE
		`users`.`id` = 1 LIMIT 1[0m
  ↳ app/controllers/application_controller.rb:6
  [1m[36mPost Load (1.0ms)[0m  [1m[34m
	SELECT
		`posts`. *
	FROM
		`posts`
	WHERE
		`posts`.`id` = 1 LIMIT 1[0m
  ↳ app/controllers/posts_controller.rb:15
  [1m[36mCACHE User Load (0.0ms)[0m  [1m[34mSELECT  `users`.* FROM `users` WHERE `users`.`id` = 1 LIMIT 1[0m  [["id", 1], ["LIMIT", 1]]
  ↳ app/controllers/posts_controller.rb:16
  [1m[35m (1.0ms)[0m  [1m[34m
	SELECT
		COUNT( * )
	FROM
		`likes`
	WHERE
		`likes`.`post_id` = 1[0m
  ↳ app/controllers/posts_controller.rb:17
  Rendering posts/show.html.erb within layouts/application
  [1m[36mLike Load (1.0ms)[0m  [1m[34m
	SELECT
		`likes`. *
	FROM
		`likes`
	WHERE
		`likes`.`user_id` = 1
		AND `likes`.`post_id` = 1 LIMIT 1[0m
  ↳ app/views/posts/show.html.erb:26
  [1m[36mComment Exists (1.0ms)[0m  [1m[34m
	SELECT
		1 AS one
	FROM
		`comments`
	WHERE
		`comments`.`post_id` = 1 LIMIT 1[0m
  ↳ app/views/posts/show.html.erb:43
  [1m[36mComment Load (1.3ms)[0m  [1m[34m
	SELECT
		`comments`. *
	FROM
		`comments`
	WHERE
		`comments`.`post_id` = 1[0m
  ↳ app/views/posts/show.html.erb:47
  Rendered collection of comments/_comment.html.erb [8 times] (34.7ms)
  Rendered posts/show.html.erb within layouts/application (111.3ms)
Completed 500 Internal Server Error in 236ms (ActiveRecord: 6.5ms)
ActionView::Template::Error (no implicit conversion of nil into String):
    2:   <p><%= simple_format(comment.comment) %></p>
    3:   <br/>
    4: 
    5:     <%= content_tag(:iframe, 'map', src:'https://www.google.com/maps/embed/v1/place?key=APIキー&q=' + comment.address, width: '100%', height: 400, frameborder: 0) %>
    6: 
    7:   <br/>
    8:   <div class="p-comment__bottomLine">
app/views/comments/_comment.html.erb:5:in `+'
app/views/comments/_comment.html.erb:5:in `_app_views_comments__comment_html_erb__95375582550985352_69815137906500'
app/views/posts/show.html.erb:47:in `_app_views_posts_show_html_erb__991977752560510296_69815134793420'

$ rails console
#<Comment id: 10, post_id: 1, name: "uuu", comment: "iii", user_id: 1, created_at: "2020-09-20 04:12:40", updated_at: "2020-09-20 04:12:40", address: "okinawa">]>
$ comment = Comment.find(10)
$ comment.address
=> "okinawa"
なので値は入っているかと思います