Hi @Anonymous,
Currently there is trigger available for My Timeline only under Microsoft Flow, and if you would like to twitter posts posted under your timeline, you may consider use the following template:
Create new tweets from facebook posts
For specific page, there is no trigger available, but we could take use of the Get Page Feed Action, then filter the posts with the created time, the following screenshots shows how to twitter with the posts created after yesterday:
Get page feed would require the Page ID, which is shown under the Facebook page URL:
https://www.facebook.com/PageName-1280337005384825/
Copy and paste the number from your Facebook page URL to the Page ID field,
Then Follow the screenshots to add the Apply to each, Compose Action, and the Compose 2 Action.
Under Condition, choose the Output of Compose as the Object Name, choose Output from Compose 2 as the value.


See the results:

You could add the Recurrence as the trigger, to have the flow trigger the tweets per the time you configured:
Run flows on a schedule
Please post back if you need any further assistance.
Regards