I am searching for a description of how i get my before/after slider on a Facebook page.
But unfortently i can’t find a prper description (maybe i am look not good).
Can you please help me and point me in the right directon?
Greetings
Hello @Marketing3 and we are happy to greet you in the best place of the Earth 
Welcome to Community, mate 
You can try to install the widget on your Facebook page, however, unfortunately, we cannot help you in this matter as your personal data will be required while the installation. We can help with the installation of widgets only on the websites, I’m very sorry.
We have the tutorial that might help you do the installation, I hope it will be helpful - How to add custom Tab to Facebook Page (in 2022).
Please keep in mind that your business must have 2000 likes on Facebook in order to install widgets. If this requirement is not met, you’ll receive an error message when attempting the install, I’m very sorry about it.
Here you can find the official information from Facebook - Tabs - Pages - Documentation - Facebook for Developers.
If there’s anything else I can do for you, please let me know.