I'm using datepicker (tempusDomini) in my backend, anyway i need,when i press a button to insert a data (date1) in my datepiker and show it.

Also when i click another button, i need to retrive the data shown in the picker.

I have folllowed the documentation on the site https://getdatepicker.com/6/examples/#picker-functions , but i reaaly don't understand how to use it.

i'm using Javascript in my frontend.