YII2 Login modification problem, how to change the default username to the drop-down menu I need?

Use YII2 's own login registration feature:
Now there is a need to develop a new station, but the user name needs to be made from the username field in the old table.

Such a style (using the Select2 JavaScript plugin), how do I hack my own user component and change the username to the data i need (existing data has been converted to JSON)? Feel YII2 with the login registration package is very good, feel no way to modify, I hope to have a master can give me answers, thank you very much.

Reply content:

Use YII2 's own login registration feature:
Now there is a need to develop a new station, but the user name needs to be made from the username field in the old table.

Such a style (using the Select2 JavaScript plugin), how do I hack my own user component and change the username to the data i need (existing data has been converted to JSON)? Feel YII2 with the login registration package is very good, feel no way to modify, I hope to have a master can give me answers, thank you very much.

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