You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
I replied in your other thread too but in case you did see that:
You must have Chrome as your default browser to sign in successfully, you can set another back as default once it is logged in
I have had this issue in Android, I worked out that you MUST have Chrome as the default browser, otherwise you will have a sign in loop. Set Chrome as your default browser, sign in to the Tesla app then set your preferred browser back as default.