Python script accessing sequence object

I work with UE 4.26.1 on macOS 10.14.6.
I have a python script that I execute in the UE4 editor.
My python script takes selected RequerdedSequence object and analyses it.

There is a line that reads the tick resolution, like:

tick_resolution = sequence.get_tick_resolution().numerator

For this call I get error

LogPython: Error: AttributeError: ‘LevelSequence’ object has no attribute ‘get_tick_resolution’

I know that I work with proper object as I do check object’s type with:

print("Is LevelSequence: " + isinstance(sequence, unreal.LevelSequence))

where sequence is my selected sequence object.

Does anyone can advise on resolving this?
This script works ok in 4.21.

PS: Official docs here says that method get_tick_resolution() exists.

Do you have the SequencerScripting plugin enabled?