Add this code inside the <head> tag of your custom code:
Add this code inside the before </body> tag of your custom code:
Firstly add an input field -
Secondly give it an ID of ‘datepicker’
Edit: if you’d like to have more than one datepicker on the same page just swap the #ID in the custom code for a .class and give each input an individual ID and you should be able to have more than one. For example this is how two datepickers would look in your custom code:
Then give the input field a CSS class of ‘datepicker’ with an ID of for example datepicker_1. Then if you want to add another give it the same class name and a new unique ID for example datepicker_2.