Facebook graph api 使用facebook graph API 4.0，如何通过编程在测试用户之间发送好友请求？

这在几年前就起作用了，但现在似乎不再起作用了。我正在使用facebook graph API以编程方式生成测试用户并发送/确认好友请求

它可以创建测试用户：

用户A

POST https://graph.facebook.com/v4.0/${APP-ID}/accounts/test-users HTTP/1.1 body{name=userA&access_token=${ACCESS-TOKEN}&installed=false}
RESPONSE: {“id":"106485800749210","login_url":"https:\/\/developers.facebook.com\/checkpoint\/test-user-login\/106485800749210\/?is_sandbox=0&sandbox_asset_type=test_user&page_id=0","email":"yciziemdeb_1568798987\u0040tfbnw.net","password":"1408448545"}

POST https://graph.facebook.com/v4.0/${APP-ID}/accounts/test-users HTTP/1.1 body{installed=true&permissions=email%2Cuser_friends&access_token=${ACCESS-TOKEN}&uid=106485800749210&owner_access_token=${OWNER-ACCESS-TOKEN}}
RESPONSE: {"id":"106485800749210","access_token":"******…","login_url":"https:\/\/developers.facebook.com\/checkpoint\/test-user-login\/106485800749210\/?is_sandbox=0&sandbox_asset_type=test_user&page_id=0","email":"yciziemdeb_1568798987\u0040tfbnw.net"}

用户B

POST https://graph.facebook.com/v4.0/${APP-ID}/accounts/test-users HTTP/1.1 body{name=userB&access_token=${ACCESS-TOKEN}&installed=false}
RESPONSE: {"id":"113912670000851","login_url":"https:\/\/developers.facebook.com\/checkpoint\/test-user-login\/113912670000851\/?is_sandbox=0&sandbox_asset_type=test_user&page_id=0","email":"pmztcoojcx_1568799008\u0040tfbnw.net","password":"2095538830"}

POST https://graph.facebook.com/v4.0/${APP-ID} accounts/test-users HTTP/1.1 body{installed=true&permissions=email+user_friends&access_token=${ACCESS-TOKEN}&uid=113912670000851&owner_access_token=${OWNER-ACCESS-TOKEN}}
RESPONSE: {"id":"113912670000851","access_token":"******…","login_url":"https:\/\/developers.facebook.com\/checkpoint\/test-user-login\/113912670000851\/?is_sandbox=0&sandbox_asset_type=test_user&page_id=0","email":"pmztcoojcx_1568799008\u0040tfbnw.net"}

但在发送好友请求时失败：

POST https://graph.facebook.com/v4.0/106485800749210/friends/113912670000851 HTTP/1.1 body{access_token=${USER.A-ACCESS-TOKEN}}
RESPONSE: Bad Request : {"error":{"message":"(#33) This object does not exist or does not support this action","type":"OAuthException","code":33,"fbtrace_id":"AhXLj4h44ydX3n0dsJO4Dj5"}}

我做错了什么？以下是facebook graph API/{user id}/friends edge的文档：