html part
<ion-select [(ngModel)]="getSelectedSubject" (ionChange)="getSelectedSubjectValue(getSelectedSubject)" [interfaceOptions]="customAlertOptions" interface="dropdown" placeholder="Select subject">
<ion-select-option value="English">English</ion-select-option>
<ion-select-option value="Mathematics">Mathematics</ion-select-option>
</ion-select>
ts part
getSelectedSubjectValue(getSelectedSubject){
console.log(getSelectedSubject)
}
just working prety good