Open Text Translation Service Page, click "Create Application" button, you will need to fill in the application information, fill in "Immersive Translate", "Utilities", "Text Translation", "API", click OK to complete the creation. Fill in "Immersive Translate", "Utilities", "Text Translation", and "API", and click OK to finish the creation.
Open App Overview Page, in the app list, find the app you just created with "App Name" as "Immersive Translate", then you will see the "App ID" and "Key/Package Name/Bundle ID", fill them into this extension Basic Settings - Translation Services - Wealthy Translator.
Done 🎉 If you have any doubts, please give feedback here.