For effective authentication in Ionic, it is recommended to utilize Ionic Auth -
The instructions provided on the linked page are quite straightforward and offer various ways to authenticate users. You have the option to use Ionic's backend services for handling authentication or manage it independently at your end by returning a JWT. Additionally, there are numerous social logins supported.
If you specifically require users to log in every time they open the app, refer to the closing section of the URL.
How can I enforce user login each time the app is accessed?
By default, users remain logged in. To implement a login requirement upon each app session, ensure to set remember: false in your login options.
this.auth.login('basic', details, {'remember': false});