Writing the same text into all selected objects

I found a script that may work for you.

http://bcrockett.com/blog/2016/12/change-or-replace-multiple-objects-in-illustrator-using-symbols/#:~:text=In%20Illustrator%2C%20go%20to%20File,the%20symbol%20you've%20created.

I created a symbol then drew a bunch of rectangles. I selected the rectangles then ran the script. It replaced each rectangle with an instance of the symbol.