加上我的意见可以说have added my comments吗？还是有其他说法？ 谢谢

Yes, you can say that.

Usually we say to add my comments to or on sth.

e.g. I have added my comments to the discussion.
e.g. I have added my comments to this post.
e.g. I have added my comments to this question.
e.g. I have added my comments on the Website.
e.g. I have added my comments on the article.

Or, you can simply say, "I have added my comments."

Hope this helps.

Cheers

In additional to my point/ with my comments

最好是用add one's opinion，comment一般表评价，用在这里也可以。