TOC for restricted content (Memberpress)

Hello,

how is it possible to get a table of contents for restricted content (behind a paywall for logged in users).

Examples:
1. How it is on my page: https://ibb.co/WBNL2w3

2. How I would like to have it: https://ibb.co/qWt1Rbf

I am using Memberpress for the content restriction and contacted them already. They say “Well, I checked your page source code and can see that table of contents is not rendered while logged out, so I recommend checking their support.”.

Please help.

Kind regards
Christian