Facebook Autoposting for Authors

Hello,

I'd like to ask for your help setting up Facebook Autoposting for Authors.
I've followed the instruction on:
https://stackideas.com/docs/easyblog/administrators/autoposting/facebook-autoposting

Now I'm at the stage of testing the Facebook app before submitting it for review/approval.
In order to submit for review, I think I need to let test user to be able to demonstrate how it works.

I've created a test user within fb app configuration page.
And testing if EasyBlog can autopost to test user's facebook account, but I cannot get it work.

Below are my settings:

Backend:
Auto Posting > Facebook >
- Application Settings: ID & Secret are entered. Connected to my Facebook account.
- Allow Authors to use their Facebook Account: Yes
(screenshot attached)

Frontend user's ACL > Profile > Update Facebook: Yes

Frontend:
- Logged in as frontend user > Profile > Facebook > Allow Access: Connected to test user's Facebook account.
- Enabled by default: OFF
(screenshot attached)

When frontend user created a new post, enabled Social Publishing by checking Facebook option.
But the post was never published on tester's Facebook account.
In the backend Auto Posting logs, it is recorded as "Invalid OAuth access token."
(I've checked test user's Access Token with facebook's Access Token Debugger. Screenshot attached.)

It would be great help if you can kindly check our app settings.
If it's OK with you, please provide me your fb ID or username so that I can add you as a Tester or Developer on fb developer's console.


FYI: If I enable "Autopost On New Post" option in Facebook Autoposting settings, the posts created by the frontend tester were published on my own Facebook account.
(What I need is that the posts created by frontend users will be published on their own Facebook account's timeline.)


Credentials necessary for testing are enclosed.

Thanks,
rikao