Hello~ it seems as of 1.19, mojang changed the entitlement files that your contain pack's Content Keys
they added some extra encryption to it
the Entitlement Files now contain the header "Version2" and then a base64 string, decoding that string is an encrypted version of what was there in 1.18, and also what is there if you connected directly to the API and requested your inventory.
The encryption works as follows
1- locate the options.txt file; usually its at
%LOCALAPPDATA%/packages/Microsoft.MinecraftUWP_8wekyb3d8bbwe/LocalState/games/com.mojang/minecraftpe/options.txt
read the "last_title_account_id" for example; 1D05A92F556ACCD5
append last_title_account_id to itself, resulting in 1D05A92F556ACCD51D05A92F556ACCD5
then XOR that with the constant "X(nG*ejm&E8)m+8c;-SkLTjF)*QdN6_Y"
the result of that XOR is the aes-128-cfb key required to decrypt the entitlement buffer, then you just read it the same way as before
which i dont think i actually explained earlier, if you want more details,
read the code
here is an updated verison to do all the new stuff they added: