SharePoint field inside Form which is of type Choice that allow multiple selection + allow fill-in

[john john]

We have a  SharePoint column of type Choice which allow multiple selection and allow Fill-in, as follow:-

now inside SharePoint built-in list form, i will get this outcomes, where users can select multiple checkboxes and/or enter custom value:-

but in power apps i will get a normal combo-box without any text to enter custom values.. so how i can fix this? so i can add/edit the value/s + view the value/s?

Current behavior inside the built-in list form, which i want to mimic inside Power Apps form:-

1) ONLY select single/multiple choice without entering custom value.

2) BOTH select single/multiple choice/s + enter a custom value

3) ONLY enter a custom value

This will work inside the Add ,Edit & View built-in list forms... so how we can have similar functionality inside power Apps form?

Here is the UI i am planning/trying to have inside the form:-

Thanks