Use Flash LED for video

[ohnonot]

Today I tried to make a short video in the dark and was challenged with the following situation:

• it was not possible to switch on the LED with any options inside the Advanced Camera UI
• switching on the LED with the Flashlight button (pull down menu) was not effective while the Adavanced Camera app was running

Did I miss something? Is it possible to light video with the phone's bright LED?

This happened on a Sony Xperia XA2 with SailfishOS 3.4