Quick and easy job for an android/kotlin developper

Close to find by myself but don't know kotlin.

1- Search and install openfoodfact application on store https://bit.ly/3mWjszo
2- Have a look on the search by category textfield (categories autocomplete) (see screenshot)
3- Download the Android/Kotlin open source code https://bit.ly/3khWOja
4- Find the full request url (shoud be something like https://world.openfoodfacts.org/cgi/search.pl with parameters
5- Expected result:
- Provide the url of the API to search aliment by category to complete result on the autocomplete category textfield
- Like the screenshot, another url for products (for selected category) may be provided to access the relevants products.

TIP:

Job have been done before, so help is offered:

API documentation urls
https://fr.openfoodfacts.org/data
https://wiki.openfoodfacts.org/API
https://world.openfoodfacts.org/cgi/search.pl

Code sources to investigate:
CategoryListFragment.kt
CategoryFragmentViewModel.kt, function searchCategories