NFC Host-based card emulation (HCE)

Ah. For that you’d need a config plugin. And if you’re going to write a config plugin you might as well generate the aid_list.xml file in that too.

See https://docs.expo.dev/guides/config-plugins/
I believe you want to use withAndroidManifest.
Clone the https://github.com/expo/expo/ repository and run this to find examples:

git grep -l withAndroidManifest -- packages/*/plugin/src/

Here are some posts on the forums that have examples too (in no particular order):

Also maybe have a look at xml2js for generating aid_list.xml.

EDIT: Here’s another example: