Eiichiro Kamiya

We apologize for the hours you spent on the plugin.
I made a small change and tested on wordpress 5.7(comming version). I hope you work on the latest version of the plugin.

Thank you very much.
I will update my plug-in.

It works under the latest wordpress.

Thank you for your advice.
At this stage of the project, I must be satisfied with what I have.