How to insert multiple values ​​into one text field using autocomplete function in Drupal

Question

I want to fill in a text box using Drupal, which allows you to use multiple values ​​using "," as a separator. I want to implement this function using drupal's autocomplete function ...

For example: if you type “J” in the text box, this gives me several options, starting with the letter “J” because of the autocomplete function. Having selected this value, I type "," and again press the keyboard key, for example, "A". Now it should give me all the available values, starting with "A".

How can i do this?

thank