How do I need to change my child's privacy settings to allow mods on Farming Simulator 25?

You need to allow user generated content

You'll find it under Privacy in account settings

I am on a windows computer and I still have no idea how to change my child's Xbox one privacy settings.

How do I allow his account to add friends?

Your Online Safety and privacy settings should be set to allow multiplayer. If it is a child account then you will need the parent account to change the settings.

To be able to play multiplayer you will need to change the setting for multiplayer to allow. It can be found under Online & Privacy settings.

If the account is a child account then a parent account will need to change these settings as mentioned.

I'm with the others here. I read EVERYWHERE to change your child's privacy settings, which I have done over and over and over. The only thing that works to allow them to play Among Us on xBox is to list them as an adult in xBox privacy settings. Nothing else works. Nothing!

Now, can you PLEASE tell us WHICH SETTINGS we need to change on our CHILD's accounts to allow them to play this game? Please be very specific about the settings - and switching from a child/teen to adult privacy settings is NOT an appropriate answer here.