Safari extension to add button and drop down-list to page upon loading

Hi, I want a Safari extension that when it is installed, each time I visit a website ([login to view URL] in example) it will add a "Copy" button, and then I click this button it will copy the text entered in the search field. I also want it to populate a drop-down list with 3 options (option 1, 2, 3) and another button "Use". When an option has been selected in the drop-down list and user click on button "Use" it will enter the text stored for either option into the search field. E.g. Option 1 = This is an example search 1 Option 2 = This is an example search 2 Option 3 = This is an example search 3 See attached image as reference and ask question if more info is needed!