Is President Biden's approval rating 11% according to Gallup? No, that's not true: Their most recent polling puts his approval rating at 54%, according to Gallup's website.
The claim appeared in a Facebook post (archived here) on April 6, 2021. It read:
New Poll indicates Biden approval at 11%. The LOWEST approval rating of ANY president in American history. ~Gallup via Daily Caller
This is what the post looked like on Facebook at the time of writing:
(Source: Facebook screenshot taken on Wed Apr 7 22:47:08 2021 UTC)
The most recent data released by Gallup as posted to its website shows that Biden's approval rating among all adults in the U.S. was at 54% as of April 7, 2021. The data shown says the number was drawn from polling performed between March 1 to March 15, 2021. Among only Republicans who were polled, his approval was only 8%, and among Democrats it was 94%.
It is unclear where the 11% figure came from, but it does not accurately reflect Gallup's survey result on Biden's approval across all Americans.